set eolstyle correctly

svn path=/trunk/mcs/; revision=156305

4 files changed, 7085 insertions, 7085 deletions

diff --git a/mcs/class/Mono.C5/C5/arrays/ArrayList.cs b/mcs/class/Mono.C5/C5/arrays/ArrayList.cs
index 2b309242cef..4fdda10e2a6 100644
--- a/mcs/class/Mono.C5/C5/arrays/ArrayList.cs
+++ b/mcs/class/Mono.C5/C5/arrays/ArrayList.cs
@@ -1,2638 +1,2638 @@
-

-/*

- Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft

- Permission is hereby granted, free of charge, to any person obtaining a copy

- of this software and associated documentation files (the "Software"), to deal

- in the Software without restriction, including without limitation the rights

- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

- copies of the Software, and to permit persons to whom the Software is

- furnished to do so, subject to the following conditions:

- 

- The above copyright notice and this permission notice shall be included in

- all copies or substantial portions of the Software.

- 

- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

- SOFTWARE.

-*/

-

-#define HASHINDEXnot

-

-using System;

-using System.Diagnostics;

-using SCG = System.Collections.Generic;

-namespace C5

-{

-  /// <summary>

-  /// A list collection based on a plain dynamic array data structure.

-  /// Expansion of the internal array is performed by doubling on demand. 

-  /// The internal array is only shrinked by the Clear method. 

-  ///

-  /// <i>When the FIFO property is set to false this class works fine as a stack of T.

-  /// When the FIFO property is set to true the class will function as a (FIFO) queue

-  /// but very inefficiently, use a LinkedList (<see cref="T:C5.LinkedList`1"/>) instead.</i>

-  /// </summary>

-  [Serializable]

-  public class ArrayList<T> : ArrayBase<T>, IList<T>, SCG.IList<T>

-#if HASHINDEX

-#else

-, IStack<T>, IQueue<T>

-#endif

-  {

-    #region Fields

-

-    /// <summary>

-    /// Has this list or view not been invalidated by some operation (by someone calling Dispose())

-    /// </summary>

-    bool isValid = true;

-

-    //TODO: wonder if we should save some memory on none-view situations by 

-    //      putting these three fields into a single ref field?

-    /// <summary>

-    /// The underlying list if we are a view, null else.

-    /// </summary>

-    ArrayList<T> underlying;

-    WeakViewList<ArrayList<T>> views;

-    WeakViewList<ArrayList<T>>.Node myWeakReference;

-

-    /// <summary>

-    /// The size of the underlying list.

-    /// </summary>

-    int underlyingsize { get { return (underlying ?? this).size; } }

-

-    /// <summary>

-    /// The underlying field of the FIFO property

-    /// </summary>

-    bool fIFO = false;

-

-#if HASHINDEX

-    HashSet<KeyValuePair<T, int>> itemIndex;

-#endif

-    #endregion

-    #region Events

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public override EventTypeEnum ListenableEvents { get { return underlying == null ? EventTypeEnum.All : EventTypeEnum.None; } }

-

-    /*

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event CollectionChangedHandler<T> CollectionChanged

-        {

-          add

-          {

-            if (underlying == null)

-              base.CollectionChanged += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.CollectionChanged -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event CollectionClearedHandler<T> CollectionCleared

-        {

-          add

-          {

-            if (underlying == null)

-              base.CollectionCleared += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.CollectionCleared -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event ItemsAddedHandler<T> ItemsAdded

-        {

-          add

-          {

-            if (underlying == null)

-              base.ItemsAdded += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.ItemsAdded -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event ItemInsertedHandler<T> ItemInserted

-        {

-          add

-          {

-            if (underlying == null)

-              base.ItemInserted += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.ItemInserted -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event ItemsRemovedHandler<T> ItemsRemoved

-        {

-          add

-          {

-            if (underlying == null)

-              base.ItemsRemoved += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.ItemsRemoved -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event ItemRemovedAtHandler<T> ItemRemovedAt

-        {

-          add

-          {

-            if (underlying == null)

-              base.ItemRemovedAt += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.ItemRemovedAt -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-          */

-

-    #endregion

-    #region Util

-

-    bool equals(T i1, T i2) { return itemequalityComparer.Equals(i1, i2); }

-

-    /// <summary>

-    /// Increment or decrement the private size fields

-    /// </summary>

-    /// <param name="delta">Increment (with sign)</param>

-    void addtosize(int delta)

-    {

-      size += delta;

-      if (underlying != null)

-        underlying.size += delta;

-    }

-

-    #region Array handling

-    /// <summary>

-    /// Double the size of the internal array.

-    /// </summary>

-    protected override void expand()

-    { expand(2 * array.Length, underlyingsize); }

-

-

-    /// <summary>

-    /// Expand the internal array, resetting the index of the first unused element.

-    /// </summary>

-    /// <param name="newcapacity">The new capacity (will be rouded upwards to a power of 2).</param>

-    /// <param name="newsize">The new count of </param>

-    protected override void expand(int newcapacity, int newsize)

-    {

-      if (underlying != null)

-        underlying.expand(newcapacity, newsize);

-      else

-      {

-        base.expand(newcapacity, newsize);

-        if (views != null)

-          foreach (ArrayList<T> v in views)

-            v.array = array;

-      }

-    }

-

-    #endregion

-

-    #region Checks

-    /// <summary>

-    /// Check if it is valid to perform updates and increment stamp if so.

-    /// </summary>

-    /// <exception cref="ViewDisposedException"> If check fails by this list being a disposed view.</exception>

-    /// <exception cref="ReadOnlyCollectionException"> If check fails by this being a read only list.</exception>

-    protected override void updatecheck()

-    {

-      validitycheck();

-      base.updatecheck();

-      if (underlying != null)

-        underlying.stamp++;

-    }

-

-

-    /// <summary>

-    /// Check if we are a view that the underlying list has only been updated through us.

-    /// <para>This method should be called from enumerators etc to guard against 

-    /// modification of the base collection.</para>

-    /// </summary>

-    /// <exception cref="ViewDisposedException"> if check fails.</exception>

-    void validitycheck()

-    {

-      if (!isValid)

-        throw new ViewDisposedException();

-    }

-

-

-    /// <summary>

-    /// Check that the list has not been updated since a particular time.

-    /// <para>To be used by enumerators and range </para>

-    /// </summary>

-    /// <exception cref="ViewDisposedException"> If check fails by this list being a disposed view.</exception>

-    /// <exception cref="CollectionModifiedException">If the list *has* beeen updated since that  time..</exception>

-    /// <param name="stamp">The stamp indicating the time.</param>

-    protected override void modifycheck(int stamp)

-    {

-      validitycheck();

-      if (this.stamp != stamp)

-        throw new CollectionModifiedException();

-    }

-

-    #endregion

-

-    #region Searching

-

-    /// <summary>

-    /// Internal version of IndexOf without modification checks.

-    /// </summary>

-    /// <param name="item">Item to look for</param>

-    /// <returns>The index of first occurrence</returns>

-    int indexOf(T item)

-    {

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item);

-      if (itemIndex.Find(ref p) && p.Value >= offset && p.Value < offset + size)

-        return p.Value - offset;

-#else

-      for (int i = 0; i < size; i++)

-        if (equals(item, array[offset + i]))

-          return i;

-#endif

-      return ~size;

-    }

-

-    /// <summary>

-    /// Internal version of LastIndexOf without modification checks.

-    /// </summary>

-    /// <param name="item">Item to look for</param>

-    /// <returns>The index of last occurrence</returns>

-    int lastIndexOf(T item)

-    {

-#if HASHINDEX

-      return indexOf(item);

-#else

-      for (int i = size - 1; i >= 0; i--)

-        if (equals(item, array[offset + i]))

-          return i;

-      return ~size;

-#endif

-    }

-    #endregion

-

-    #region Inserting

-

-#if HASHINDEX

-    /// <summary>

-    /// Internal version of Insert with no modification checks.

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException"> if item already in list.</exception>

-    /// <param name="i">Index to insert at</param>

-    /// <param name="item">Item to insert</param>

-#else

-    /// <summary>

-    /// Internal version of Insert with no modification checks.

-    /// </summary>

-    /// <param name="i">Index to insert at</param>

-    /// <param name="item">Item to insert</param>

-#endif

-    protected override void insert(int i, T item)

-    {

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, offset + i);

-      if (itemIndex.FindOrAdd(ref p))

-        throw new DuplicateNotAllowedException("Item already in indexed list: " + item);

-#endif

-      baseinsert(i, item);

-#if HASHINDEX

-      reindex(i + offset + 1);

-#endif

-    }

-

-    private void baseinsert(int i, T item)

-    {

-      if (underlyingsize == array.Length)

-        expand();

-      i += offset;

-      if (i < underlyingsize)

-        Array.Copy(array, i, array, i + 1, underlyingsize - i);

-      array[i] = item;

-      addtosize(1);

-      fixViewsAfterInsert(1, i);

-    }

-    #endregion

-

-    #region Removing

-

-    /// <summary>

-    /// Internal version of RemoveAt with no modification checks.

-    /// </summary>

-    /// <param name="i">Index to remove at</param>

-    /// <returns>The removed item</returns>

-    T removeAt(int i)

-    {

-      i += offset;

-      fixViewsBeforeSingleRemove(i);

-      T retval = array[i];

-      addtosize(-1);

-      if (underlyingsize > i)

-        Array.Copy(array, i + 1, array, i, underlyingsize - i);

-      array[underlyingsize] = default(T);

-#if HASHINDEX

-      itemIndex.Remove(new KeyValuePair<T, int>(retval));

-      reindex(i);

-#endif

-      return retval;

-    }

-    #endregion

-

-    #region Indexing

-

-#if HASHINDEX

-    private void reindex(int start) { reindex(start, underlyingsize); }

-

-    private void reindex(int start, int end)

-    {

-      for (int j = start; j < end; j++)

-        itemIndex.UpdateOrAdd(new KeyValuePair<T, int>(array[j], j));

-    }

-#endif

-    #endregion

-

-    #region fixView utilities

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="added">The actual number of inserted nodes</param>

-    /// <param name="realInsertionIndex"></param>

-    void fixViewsAfterInsert(int added, int realInsertionIndex)

-    {

-      if (views != null)

-        foreach (ArrayList<T> view in views)

-        {

-          if (view != this)

-          {

-            if (view.offset < realInsertionIndex && view.offset + view.size > realInsertionIndex)

-              view.size += added;

-            if (view.offset > realInsertionIndex || (view.offset == realInsertionIndex && view.size > 0))

-              view.offset += added;

-          }

-        }

-    }

-

-    void fixViewsBeforeSingleRemove(int realRemovalIndex)

-    {

-      if (views != null)

-        foreach (ArrayList<T> view in views)

-        {

-          if (view != this)

-          {

-            if (view.offset <= realRemovalIndex && view.offset + view.size > realRemovalIndex)

-              view.size--;

-            if (view.offset > realRemovalIndex)

-              view.offset--;

-          }

-        }

-    }

-

-    /// <summary>

-    /// Fix offsets and sizes of other views before removing an interval from this 

-    /// </summary>

-    /// <param name="start">the start of the interval relative to the array/underlying</param>

-    /// <param name="count"></param>

-    void fixViewsBeforeRemove(int start, int count)

-    {

-      int clearend = start + count - 1;

-      if (views != null)

-        foreach (ArrayList<T> view in views)

-        {

-          if (view == this)

-            continue;

-          int viewoffset = view.offset, viewend = viewoffset + view.size - 1;

-          if (start < viewoffset)

-          {

-            if (clearend < viewoffset)

-              view.offset = viewoffset - count;

-            else

-            {

-              view.offset = start;

-              view.size = clearend < viewend ? viewend - clearend : 0;

-            }

-          }

-          else if (start <= viewend)

-            view.size = clearend <= viewend ? view.size - count : start - viewoffset;

-        }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="otherOffset"></param>

-    /// <param name="otherSize"></param>

-    /// <returns>The position of View(otherOffset, otherSize) wrt. this view</returns>

-    MutualViewPosition viewPosition(int otherOffset, int otherSize)

-    {

-      int end = offset + size, otherEnd = otherOffset + otherSize;

-      if (otherOffset >= end || otherEnd <= offset)

-        return MutualViewPosition.NonOverlapping;

-      if (size == 0 || (otherOffset <= offset && end <= otherEnd))

-        return MutualViewPosition.Contains;

-      if (otherSize == 0 || (offset <= otherOffset && otherEnd <= end))

-        return MutualViewPosition.ContainedIn;

-      return MutualViewPosition.Overlapping;

-    }

-

-    //TODO: make version that fits the new, more forgiving rules for disposing

-    void disposeOverlappingViews(bool reverse)

-    {

-      if (views != null)

-        foreach (ArrayList<T> view in views)

-        {

-          if (view != this)

-          {

-            switch (viewPosition(view.offset, view.size))

-            {

-              case MutualViewPosition.ContainedIn:

-                if (reverse)

-                  view.offset = 2 * offset + size - view.size - view.offset;

-                else

-                  view.Dispose();

-                break;

-              case MutualViewPosition.Overlapping:

-                view.Dispose();

-                break;

-              case MutualViewPosition.Contains:

-              case MutualViewPosition.NonOverlapping:

-                break;

-            }

-          }

-        }

-    }

-    #endregion

-

-    #endregion

-

-    #region Position, PositionComparer and ViewHandler nested types

-    class PositionComparer : SCG.IComparer<Position>

-    {

-      public int Compare(Position a, Position b)

-      {

-        return a.index.CompareTo(b.index);

-      }

-    }

-    /// <summary>

-    /// During RemoveAll, we need to cache the original endpoint indices of views (??? also for ArrayList?)

-    /// </summary>

-    struct Position

-    {

-      public readonly ArrayList<T> view;

-      public readonly int index;

-      public Position(ArrayList<T> view, bool left)

-      {

-        this.view = view;

-        index = left ? view.offset : view.offset + view.size - 1;

-      }

-      public Position(int index) { this.index = index; view = null; }

-    }

-

-    /// <summary>

-    /// Handle the update of (other) views during a multi-remove operation.

-    /// </summary>

-    struct ViewHandler

-    {

-      ArrayList<Position> leftEnds;

-      ArrayList<Position> rightEnds;

-      int leftEndIndex, rightEndIndex;

-      internal readonly int viewCount;

-      internal ViewHandler(ArrayList<T> list)

-      {

-        leftEndIndex = rightEndIndex = viewCount = 0;

-        leftEnds = rightEnds = null;

-        if (list.views != null)

-          foreach (ArrayList<T> v in list.views)

-            if (v != list)

-            {

-              if (leftEnds == null)

-              {

-                leftEnds = new ArrayList<Position>();

-                rightEnds = new ArrayList<Position>();

-              }

-              leftEnds.Add(new Position(v, true));

-              rightEnds.Add(new Position(v, false));

-            }

-        if (leftEnds == null)

-          return;

-        viewCount = leftEnds.Count;

-        leftEnds.Sort(new PositionComparer());

-        rightEnds.Sort(new PositionComparer());

-      }

-      /// <summary>

-      /// This is to be called with realindex pointing to the first node to be removed after a (stretch of) node that was not removed

-      /// </summary>

-      /// <param name="removed"></param>

-      /// <param name="realindex"></param>

-      internal void skipEndpoints(int removed, int realindex)

-      {

-        if (viewCount > 0)

-        {

-          Position endpoint;

-          while (leftEndIndex < viewCount && (endpoint = leftEnds[leftEndIndex]).index <= realindex)

-          {

-            ArrayList<T> view = endpoint.view;

-            view.offset = view.offset - removed;

-            view.size += removed;

-            leftEndIndex++;

-          }

-          while (rightEndIndex < viewCount && (endpoint = rightEnds[rightEndIndex]).index < realindex)

-          {

-            endpoint.view.size -= removed;

-            rightEndIndex++;

-          }

-        }

-      }

-      internal void updateViewSizesAndCounts(int removed, int realindex)

-      {

-        if (viewCount > 0)

-        {

-          Position endpoint;

-          while (leftEndIndex < viewCount && (endpoint = leftEnds[leftEndIndex]).index <= realindex)

-          {

-            ArrayList<T> view = endpoint.view;

-            view.offset = view.Offset - removed;

-            view.size += removed;

-            leftEndIndex++;

-          }

-          while (rightEndIndex < viewCount && (endpoint = rightEnds[rightEndIndex]).index < realindex)

-          {

-            endpoint.view.size -= removed;

-            rightEndIndex++;

-          }

-        }

-      }

-    }

-    #endregion

-

-    #region Constructors

-    /// <summary>

-    /// Create an array list with default item equalityComparer and initial capacity 8 items.

-    /// </summary>

-    public ArrayList() : this(8) { }

-

-

-    /// <summary>

-    /// Create an array list with external item equalityComparer and initial capacity 8 items.

-    /// </summary>

-    /// <param name="itemequalityComparer">The external item equalityComparer</param>

-    public ArrayList(SCG.IEqualityComparer<T> itemequalityComparer) : this(8, itemequalityComparer) { }

-

-

-    /// <summary>

-    /// Create an array list with default item equalityComparer and prescribed initial capacity.

-    /// </summary>

-    /// <param name="capacity">The prescribed capacity</param>

-    public ArrayList(int capacity) : this(capacity, EqualityComparer<T>.Default) { }

-

-

-    /// <summary>

-    /// Create an array list with external item equalityComparer and prescribed initial capacity.

-    /// </summary>

-    /// <param name="capacity">The prescribed capacity</param>

-    /// <param name="itemequalityComparer">The external item equalityComparer</param>

-    public ArrayList(int capacity, SCG.IEqualityComparer<T> itemequalityComparer)

-      : base(capacity, itemequalityComparer)

-    {

-#if HASHINDEX

-      itemIndex = new HashSet<KeyValuePair<T, int>>(new KeyValuePairEqualityComparer<T, int>(itemequalityComparer));

-#endif

-    }

-

-    #endregion

-

-    #region IList<T> Members

-

-    /// <summary>

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <value>The first item in this list.</value>

-    [Tested]

-    public virtual T First

-    {

-      [Tested]

-      get

-      {

-        validitycheck();

-        if (size == 0)

-          throw new NoSuchItemException();

-

-        return array[offset];

-      }

-    }

-

-

-    /// <summary>

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <value>The last item in this list.</value>

-    [Tested]

-    public virtual T Last

-    {

-      [Tested]

-      get

-      {

-        validitycheck();

-        if (size == 0)

-          throw new NoSuchItemException();

-

-        return array[offset + size - 1];

-      }

-    }

-

-

-    /// <summary>

-    /// Since <code>Add(T item)</code> always add at the end of the list,

-    /// this describes if list has FIFO or LIFO semantics.

-    /// </summary>

-    /// <value>True if the <code>Remove()</code> operation removes from the

-    /// start of the list, false if it removes from the end. The default for a new array list is false.</value>

-    [Tested]

-    public virtual bool FIFO

-    {

-      [Tested]

-      get { validitycheck(); return fIFO; }

-      [Tested]

-      set { updatecheck(); fIFO = value; }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    public virtual bool IsFixedSize

-    {

-      get { validitycheck(); return false; }

-    }

-

-

-#if HASHINDEX

-    /// <summary>

-    /// On this list, this indexer is read/write.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt;= the size of the collection.</exception>

-    /// <exception cref="DuplicateNotAllowedException"> By the get operation

-    /// if the item already is present somewhere else in the list.</exception>

-    /// <value>The index'th item of this list.</value>

-    /// <param name="index">The index of the item to fetch or store.</param>

-#else

-    /// <summary>

-    /// On this list, this indexer is read/write.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt;= the size of the collection.</exception>

-    /// <value>The index'th item of this list.</value>

-    /// <param name="index">The index of the item to fetch or store.</param>

-#endif

-    [Tested]

-    public virtual T this[int index]

-    {

-      [Tested]

-      get

-      {

-        validitycheck();

-        if (index < 0 || index >= size)

-          throw new IndexOutOfRangeException();

-

-        return array[offset + index];

-      }

-      [Tested]

-      set

-      {

-        updatecheck();

-        if (index < 0 || index >= size)

-          throw new IndexOutOfRangeException();

-        index += offset;

-        T item = array[index];

-#if HASHINDEX

-        KeyValuePair<T, int> p = new KeyValuePair<T, int>(value, index);

-        if (itemequalityComparer.Equals(value, item))

-        {

-          array[index] = value;

-          itemIndex.Update(p);

-        }

-        else if (!itemIndex.FindOrAdd(ref p))

-        {

-          itemIndex.Remove(new KeyValuePair<T, int>(item));

-          array[index] = value;

-        }

-        else

-          throw new DuplicateNotAllowedException("Item already in indexed list");

-#else

-        array[index] = value;

-#endif

-        (underlying ?? this).raiseForSetThis(index, value, item);

-      }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public virtual Speed IndexingSpeed { get { return Speed.Constant; } }

-

-#if HASHINDEX

-    /// <summary>

-    /// Insert an item at a specific index location in this list. 

-    ///</summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt; the size of the collection. </exception>

-    /// <exception cref="DuplicateNotAllowedException"> 

-    /// If the item is already present in the list.</exception>

-    /// <param name="index">The index at which to insert.</param>

-    /// <param name="item">The item to insert.</param>

-#else

-    /// <summary>

-    /// Insert an item at a specific index location in this list. 

-    ///</summary>

-    /// <exception cref="IndexOutOfRangeException"> if i is negative or

-    /// &gt; the size of the collection. </exception>

-    /// <param name="index">The index at which to insert.</param>

-    /// <param name="item">The item to insert.</param>

-#endif

-    [Tested]

-    public virtual void Insert(int index, T item)

-    {

-      updatecheck();

-      if (index < 0 || index > size)

-        throw new IndexOutOfRangeException();

-

-      insert(index, item);

-      (underlying ?? this).raiseForInsert(index + offset, item);

-    }

-

-    /// <summary>

-    /// Insert an item at the end of a compatible view, used as a pointer.

-    /// <para>The <code>pointer</code> must be a view on the same list as

-    /// <code>this</code> and the endpoitn of <code>pointer</code> must be

-    /// a valid insertion point of <code>this</code></para>

-    /// </summary>

-    /// <exception cref="IncompatibleViewException">If <code>pointer</code> 

-    /// is not a view on or the same list as <code>this</code></exception>

-    /// <exception cref="IndexOutOfRangeException"><b>??????</b> if the endpoint of 

-    ///  <code>pointer</code> is not inside <code>this</code></exception>

-    /// <exception cref="DuplicateNotAllowedException"> if the list has

-    /// <code>AllowsDuplicates==false</code> and the item is 

-    /// already in the list.</exception>

-    /// <param name="pointer"></param>

-    /// <param name="item"></param>

-    public void Insert(IList<T> pointer, T item)

-    {

-      if ((pointer == null) || ((pointer.Underlying ?? pointer) != (underlying ?? this)))

-        throw new IncompatibleViewException();

-      Insert(pointer.Offset + pointer.Count - Offset, item);

-    }

-

-#if HASHINDEX

-    /// <summary>

-    /// Insert into this list all items from an enumerable collection starting 

-    /// at a particular index.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt; the size of the collection.</exception>

-    /// <exception cref="DuplicateNotAllowedException"> If <code>items</code> 

-    /// contains duplicates or some item already  present in the list.</exception>

-    /// <param name="index">Index to start inserting at</param>

-    /// <param name="items">Items to insert</param>

-#else

-    /// <summary>

-    /// Insert into this list all items from an enumerable collection starting 

-    /// at a particular index.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt; the size of the collection.</exception>

-    /// <param name="index">Index to start inserting at</param>

-    /// <param name="items">Items to insert</param>

-    /// <typeparam name="U"></typeparam>

-#endif

-    [Tested]

-    public virtual void InsertAll<U>(int index, SCG.IEnumerable<U> items) where U : T

-    {

-      updatecheck();

-      if (index < 0 || index > size)

-        throw new IndexOutOfRangeException();

-      index += offset;

-      int toadd = EnumerableBase<U>.countItems(items);

-      if (toadd == 0)

-        return;

-      if (toadd + underlyingsize > array.Length)

-        expand(toadd + underlyingsize, underlyingsize);

-      if (underlyingsize > index)

-        Array.Copy(array, index, array, index + toadd, underlyingsize - index);

-      int i = index;

-      try

-      {

-

-        foreach (T item in items)

-        {

-#if HASHINDEX

-          KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, i);

-          if (itemIndex.FindOrAdd(ref p))

-            throw new DuplicateNotAllowedException("Item already in indexed list");

-#endif

-          array[i++] = item;

-        }

-      }

-      finally

-      {

-        int added = i - index;

-        if (added < toadd)

-        {

-          Array.Copy(array, index + toadd, array, i, underlyingsize - index);

-          Array.Clear(array, underlyingsize + added, toadd - added);

-        }

-        if (added > 0)

-        {

-          addtosize(added);

-#if HASHINDEX

-          reindex(i);

-#endif

-          fixViewsAfterInsert(added, index);

-          (underlying ?? this).raiseForInsertAll(index, added);

-        }

-      }

-    }

-    private void raiseForInsertAll(int index, int added)

-    {

-      if (ActiveEvents != 0)

-      {

-        if ((ActiveEvents & (EventTypeEnum.Added | EventTypeEnum.Inserted)) != 0)

-          for (int j = index; j < index + added; j++)

-          {

-            raiseItemInserted(array[j], j);

-            raiseItemsAdded(array[j], 1);

-          }

-        raiseCollectionChanged();

-      }

-    }

-

-#if HASHINDEX

-    /// <summary>

-    /// Insert an item at the front of this list;

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException">If the item is already in the list</exception>

-    /// <param name="item">The item to insert.</param>

-#else

-    /// <summary>

-    /// Insert an item at the front of this list;

-    /// </summary>

-    /// <param name="item">The item to insert.</param>

-#endif

-    [Tested]

-    public virtual void InsertFirst(T item)

-    {

-      updatecheck();

-      insert(0, item);

-      (underlying ?? this).raiseForInsert(offset, item);

-    }

-

-

-#if HASHINDEX

-    /// <summary>

-    /// Insert an item at the back of this list.

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException">If the item is already in the list</exception>

-    /// <param name="item">The item to insert.</param>

-#else

-    /// <summary>

-    /// Insert an item at the back of this list.

-    /// </summary>

-    /// <param name="item">The item to insert.</param>

-#endif

-    [Tested]

-    public virtual void InsertLast(T item)

-    {

-      updatecheck();

-      insert(size, item);

-      (underlying ?? this).raiseForInsert(size - 1 + offset, item);

-    }

-

-

-    //NOTE: if the filter throws an exception, no result will be returned.

-    /// <summary>

-    /// Create a new list consisting of the items of this list satisfying a 

-    /// certain predicate.

-    /// <para>The new list will be of type ArrayList</para>

-    /// </summary>

-    /// <param name="filter">The filter delegate defining the predicate.</param>

-    /// <returns>The new list.</returns>

-    [Tested]

-    public virtual IList<T> FindAll(Fun<T, bool> filter)

-    {

-      validitycheck();

-      int stamp = this.stamp;

-      ArrayList<T> res = new ArrayList<T>(itemequalityComparer);

-      int j = 0, rescap = res.array.Length;

-      for (int i = 0; i < size; i++)

-      {

-        T a = array[offset + i];

-        bool found = filter(a);

-        modifycheck(stamp);

-        if (found)

-        {

-          if (j == rescap) res.expand(rescap = 2 * rescap, j);

-          res.array[j++] = a;

-        }

-      }

-      res.size = j;

-#if HASHINDEX

-      res.reindex(0);

-#endif

-      return res;

-    }

-

-

-#if HASHINDEX

-    /// <summary>

-    /// Create a new list consisting of the results of mapping all items of this

-    /// list. The new list will use the default item equalityComparer for the item type V.

-    /// <para>The new list will be of type ArrayList</para>

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException">If <code>mapper</code>

-    /// creates duplicates</exception>

-    /// <typeparam name="V">The type of items of the new list</typeparam>

-    /// <param name="mapper">The delegate defining the map.</param>

-    /// <returns>The new list.</returns>

-#else

-    /// <summary>

-    /// Create a new list consisting of the results of mapping all items of this

-    /// list. The new list will use the default item equalityComparer for the item type V.

-    /// <para>The new list will be of type ArrayList</para>

-    /// </summary>

-    /// <typeparam name="V">The type of items of the new list</typeparam>

-    /// <param name="mapper">The delegate defining the map.</param>

-    /// <returns>The new list.</returns>

-#endif

-    [Tested]

-    public virtual IList<V> Map<V>(Fun<T, V> mapper)

-    {

-      validitycheck();

-

-      ArrayList<V> res = new ArrayList<V>(size);

-

-      return map<V>(mapper, res);

-    }

-

-#if HASHINDEX

-    /// <summary>

-    /// Create a new list consisting of the results of mapping all items of this

-    /// list. The new list will use a specified item equalityComparer for the item type.

-    /// <para>The new list will be of type ArrayList</para>

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException">If <code>mapper</code>

-    /// creates duplicates</exception>

-    /// <typeparam name="V">The type of items of the new list</typeparam>

-    /// <param name="mapper">The delegate defining the map.</param>

-    /// <param name="itemequalityComparer">The item equalityComparer to use for the new list</param>

-    /// <returns>The new list.</returns>

-#else

-    /// <summary>

-    /// Create a new list consisting of the results of mapping all items of this

-    /// list. The new list will use a specified item equalityComparer for the item type.

-    /// <para>The new list will be of type ArrayList</para>

-    /// </summary>

-    /// <typeparam name="V">The type of items of the new list</typeparam>

-    /// <param name="mapper">The delegate defining the map.</param>

-    /// <param name="itemequalityComparer">The item equalityComparer to use for the new list</param>

-    /// <returns>The new list.</returns>

-#endif

-    public virtual IList<V> Map<V>(Fun<T, V> mapper, SCG.IEqualityComparer<V> itemequalityComparer)

-    {

-      validitycheck();

-

-      ArrayList<V> res = new ArrayList<V>(size, itemequalityComparer);

-

-      return map<V>(mapper, res);

-    }

-

-    private IList<V> map<V>(Fun<T, V> mapper, ArrayList<V> res)

-    {

-      int stamp = this.stamp;

-      if (size > 0)

-        for (int i = 0; i < size; i++)

-        {

-          V mappeditem = mapper(array[offset + i]);

-          modifycheck(stamp);

-#if HASHINDEX

-          KeyValuePair<V, int> p = new KeyValuePair<V, int>(mappeditem, i);

-          if (res.itemIndex.FindOrAdd(ref p))

-            throw new ArgumentException("Mapped item already in indexed list");

-#endif

-          res.array[i] = mappeditem;

-        }

-      res.size = size;

-      return res;

-    }

-

-    /// <summary>

-    /// Remove one item from the list: from the front if <code>FIFO</code>

-    /// is true, else from the back.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public virtual T Remove()

-    {

-      updatecheck();

-      if (size == 0)

-        throw new NoSuchItemException("List is empty");

-

-      T item = removeAt(fIFO ? 0 : size - 1);

-      (underlying ?? this).raiseForRemove(item);

-      return item;

-    }

-

-    /// <summary>

-    /// Remove one item from the fromnt of the list.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public virtual T RemoveFirst()

-    {

-      updatecheck();

-      if (size == 0)

-        throw new NoSuchItemException("List is empty");

-

-      T item = removeAt(0);

-      (underlying ?? this).raiseForRemoveAt(offset, item);

-      return item;

-    }

-

-

-    /// <summary>

-    /// Remove one item from the back of the list.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public virtual T RemoveLast()

-    {

-      updatecheck();

-      if (size == 0)

-        throw new NoSuchItemException("List is empty");

-

-      T item = removeAt(size - 1);

-      (underlying ?? this).raiseForRemoveAt(size + offset, item);

-      return item;

-    }

-

-    /// <summary>

-    /// Create a list view on this list. 

-    /// </summary>

-    /// <exception cref="ArgumentOutOfRangeException"> if the start or count is negative

-    /// or the range does not fit within list.</exception>

-    /// <param name="start">The index in this list of the start of the view.</param>

-    /// <param name="count">The size of the view.</param>

-    /// <returns>The new list view.</returns>

-    [Tested]

-    public virtual IList<T> View(int start, int count)

-    {

-      validitycheck();

-      checkRange(start, count);

-      if (views == null)

-        views = new WeakViewList<ArrayList<T>>();

-      ArrayList<T> retval = (ArrayList<T>)MemberwiseClone();

-

-

-      retval.underlying = underlying != null ? underlying : this;

-      retval.offset = start + offset;

-      retval.size = count;

-      retval.myWeakReference = views.Add(retval);

-      return retval;

-    }

-

-    /// <summary>

-    /// Create a list view on this list containing the (first) occurrence of a particular item.

-    /// <para>Returns <code>null</code> if the item is not in this list.</para>

-    /// </summary>

-    /// <param name="item">The item to find.</param>

-    /// <returns>The new list view.</returns>

-    [Tested]

-    public virtual IList<T> ViewOf(T item)

-    {

-      int index = indexOf(item);

-      if (index < 0)

-        return null;

-      return View(index, 1);

-    }

-

-

-    /// <summary>

-    /// Create a list view on this list containing the last occurrence of a particular item. 

-    /// <para>Returns <code>null</code> if the item is not in this list.</para>

-    /// </summary>

-    /// <param name="item">The item to find.</param>

-    /// <returns>The new list view.</returns>

-    [Tested]

-    public virtual IList<T> LastViewOf(T item)

-    {

-      int index = lastIndexOf(item);

-      if (index < 0)

-        return null;

-      return View(index, 1);

-    }

-

-    /// <summary>

-    /// Null if this list is not a view.

-    /// </summary>

-    /// <value>Underlying list for view.</value>

-    [Tested]

-    public virtual IList<T> Underlying { [Tested]get { return underlying; } }

-

-

-    /// <summary>

-    /// </summary>

-    /// <value>Offset for this list view or 0 for an underlying list.</value>

-    [Tested]

-    public virtual int Offset { [Tested]get { return offset; } }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public virtual bool IsValid { get { return isValid; } }

-

-    /// <summary>

-    /// Slide this list view along the underlying list.

-    /// </summary>

-    /// <exception cref="NotAViewException"> if this list is not a view.</exception>

-    /// <exception cref="ArgumentOutOfRangeException"> if the operation

-    /// would bring either end of the view outside the underlying list.</exception>

-    /// <param name="offset">The signed amount to slide: positive to slide

-    /// towards the end.</param>

-    [Tested]

-    public virtual IList<T> Slide(int offset)

-    {

-      if (!TrySlide(offset, size))

-        throw new ArgumentOutOfRangeException();

-      return this;

-    }

-

-

-    /// <summary>

-    /// Slide this list view along the underlying list, changing its size.

-    /// </summary>

-    /// <exception cref="NotAViewException"> if this list is not a view.</exception>

-    /// <exception cref="ArgumentOutOfRangeException"> if the operation

-    /// would bring either end of the view outside the underlying list.</exception>

-    /// <param name="offset">The signed amount to slide: positive to slide

-    /// towards the end.</param>

-    /// <param name="size">The new size of the view.</param>

-    [Tested]

-    public virtual IList<T> Slide(int offset, int size)

-    {

-      if (!TrySlide(offset, size))

-        throw new ArgumentOutOfRangeException();

-      return this;

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <exception cref="NotAViewException"> if this list is not a view.</exception>

-    /// <param name="offset"></param>

-    /// <returns></returns>

-    [Tested]

-    public virtual bool TrySlide(int offset)

-    {

-      return TrySlide(offset, size);

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <exception cref="NotAViewException"> if this list is not a view.</exception>

-    /// <param name="offset"></param>

-    /// <param name="size"></param>

-    /// <returns></returns>

-    [Tested]

-    public virtual bool TrySlide(int offset, int size)

-    {

-      updatecheck();

-      if (underlying == null)

-        throw new NotAViewException("Not a view");

-

-      int newoffset = this.offset + offset;

-      int newsize = size;

-

-      if (newoffset < 0 || newsize < 0 || newoffset + newsize > underlyingsize)

-        return false;

-

-      this.offset = newoffset;

-      this.size = newsize;

-      return true;

-    }

-

-    /// <summary>

-    /// 

-    /// <para>Returns null if <code>otherView</code> is strictly to the left of this view</para>

-    /// </summary>

-    /// <param name="otherView"></param>

-    /// <exception cref="IncompatibleViewException">If otherView does not have the same underlying list as this</exception>

-    /// <returns></returns>

-    public virtual IList<T> Span(IList<T> otherView)

-    {

-      if ((otherView == null) || ((otherView.Underlying ?? otherView) != (underlying ?? this)))

-        throw new IncompatibleViewException();

-      if (otherView.Offset + otherView.Count - Offset < 0)

-        return null;

-      return (underlying ?? this).View(Offset, otherView.Offset + otherView.Count - Offset);

-    }

-

-    /// <summary>

-    /// Reverst the list so the items are in the opposite sequence order.

-    /// </summary>

-    [Tested]

-    public virtual void Reverse()

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      for (int i = 0, length = size / 2, end = offset + size - 1; i < length; i++)

-      {

-        T swap = array[offset + i];

-

-        array[offset + i] = array[end - i];

-        array[end - i] = swap;

-      }

-#if HASHINDEX

-      reindex(offset, offset + size);

-#endif

-      //TODO: be more forgiving wrt. disposing

-      disposeOverlappingViews(true);

-      (underlying ?? this).raiseCollectionChanged();

-    }

-

-    /// <summary>

-    /// Check if this list is sorted according to the default sorting order

-    /// for the item type T, as defined by the <see cref="T:C5.Comparer`1"/> class 

-    /// </summary>

-    /// <exception cref="NotComparableException">if T is not comparable</exception>

-    /// <returns>True if the list is sorted, else false.</returns>

-    [Tested]

-    public bool IsSorted() { return IsSorted(Comparer<T>.Default); }

-

-    /// <summary>

-    /// Check if this list is sorted according to a specific sorting order.

-    /// </summary>

-    /// <param name="c">The comparer defining the sorting order.</param>

-    /// <returns>True if the list is sorted, else false.</returns>

-    [Tested]

-    public virtual bool IsSorted(SCG.IComparer<T> c)

-    {

-      validitycheck();

-      for (int i = offset + 1, end = offset + size; i < end; i++)

-        if (c.Compare(array[i - 1], array[i]) > 0)

-          return false;

-

-      return true;

-    }

-

-    /// <summary>

-    /// Sort the items of the list according to the default sorting order

-    /// for the item type T, as defined by the Comparer[T] class 

-    /// (<see cref="T:C5.Comparer`1"/>).

-    /// </summary>

-    /// <exception cref="InvalidOperationException">if T is not comparable</exception>

-    public virtual void Sort()

-    {

-      Sort(Comparer<T>.Default);

-    }

-

-

-    /// <summary>

-    /// Sort the items of the list according to a specific sorting order.

-    /// </summary>

-    /// <param name="comparer">The comparer defining the sorting order.</param>

-    [Tested]

-    public virtual void Sort(SCG.IComparer<T> comparer)

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      Sorting.IntroSort<T>(array, offset, size, comparer);

-      disposeOverlappingViews(false);

-#if HASHINDEX

-      reindex(offset, offset + size);

-#endif

-      (underlying ?? this).raiseCollectionChanged();

-    }

-

-

-    /// <summary>

-    /// Randomly shuffle the items of this list. 

-    /// </summary>

-    public virtual void Shuffle() { Shuffle(new C5Random()); }

-

-

-    /// <summary>

-    /// Shuffle the items of this list according to a specific random source.

-    /// </summary>

-    /// <param name="rnd">The random source.</param>

-    public virtual void Shuffle(Random rnd)

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      for (int i = offset, top = offset + size, end = top - 1; i < end; i++)

-      {

-        int j = rnd.Next(i, top);

-        if (j != i)

-        {

-          T tmp = array[i];

-          array[i] = array[j];

-          array[j] = tmp;

-        }

-      }

-      disposeOverlappingViews(false);

-#if HASHINDEX

-      reindex(offset, offset + size);

-#endif

-      (underlying ?? this).raiseCollectionChanged();

-    }

-    #endregion

-

-    #region IIndexed<T> Members

-

-    /// <summary>

-    /// Search for an item in the list going forwrds from the start.

-    /// </summary>

-    /// <param name="item">Item to search for.</param>

-    /// <returns>Index of item from start.</returns>

-    [Tested]

-    public virtual int IndexOf(T item) { validitycheck(); return indexOf(item); }

-

-

-    /// <summary>

-    /// Search for an item in the list going backwords from the end.

-    /// </summary>

-    /// <param name="item">Item to search for.</param>

-    /// <returns>Index of item from the end.</returns>

-    [Tested]

-    public virtual int LastIndexOf(T item) { validitycheck(); return lastIndexOf(item); }

-

-

-    /// <summary>

-    /// Remove the item at a specific position of the list.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt;= the size of the collection.</exception>

-    /// <param name="index">The index of the item to remove.</param>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public virtual T RemoveAt(int index)

-    {

-      updatecheck();

-      if (index < 0 || index >= size)

-        throw new IndexOutOfRangeException("Index out of range for sequenced collection");

-

-      T item = removeAt(index);

-      (underlying ?? this).raiseForRemoveAt(offset + index, item);

-      return item;

-    }

-

-

-    /// <summary>

-    /// Remove all items in an index interval.

-    /// </summary>

-    /// <exception cref="ArgumentOutOfRangeException">If <code>start</code>

-    /// and <code>count</code> does not describe a valid interval in the list</exception> 

-    /// <param name="start">The index of the first item to remove.</param>

-    /// <param name="count">The number of items to remove.</param>

-    [Tested]

-    public virtual void RemoveInterval(int start, int count)

-    {

-      updatecheck();

-      if (count == 0)

-        return;

-      checkRange(start, count);

-      start += offset;

-      fixViewsBeforeRemove(start, count);

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-      for (int i = start, end = start + count; i < end; i++)

-      {

-        p.Key = array[i];

-        itemIndex.Remove(p);

-      }

-#endif

-      Array.Copy(array, start + count, array, start, underlyingsize - start - count);

-      addtosize(-count);

-      Array.Clear(array, underlyingsize, count);

-#if HASHINDEX

-      reindex(start);

-#endif

-      (underlying ?? this).raiseForRemoveInterval(start, count);

-    }

-    void raiseForRemoveInterval(int start, int count)

-    {

-      if (ActiveEvents != 0)

-      {

-        raiseCollectionCleared(size == 0, count, start);

-        raiseCollectionChanged();

-      }

-    }

-    #endregion

-

-    #region ICollection<T> Members

-

-    /// <summary>

-    /// The value is symbolic indicating the type of asymptotic complexity

-    /// in terms of the size of this collection (worst-case or amortized as

-    /// relevant).

-    /// </summary>

-    /// <value>Speed.Linear</value>

-    [Tested]

-    public virtual Speed ContainsSpeed

-    {

-      [Tested]

-      get

-      {

-#if HASHINDEX

-        return Speed.Constant;

-#else

-        return Speed.Linear;

-#endif

-      }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    [Tested]

-    public override int GetUnsequencedHashCode()

-    { validitycheck(); return base.GetUnsequencedHashCode(); }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="that"></param>

-    /// <returns></returns>

-    [Tested]

-    public override bool UnsequencedEquals(ICollection<T> that)

-    { validitycheck(); return base.UnsequencedEquals(that); }

-

-    /// <summary>

-    /// Check if this collection contains (an item equivalent to according to the

-    /// itemequalityComparer) a particular value.

-    /// </summary>

-    /// <param name="item">The value to check for.</param>

-    /// <returns>True if the items is in this collection.</returns>

-    [Tested]

-    public virtual bool Contains(T item)

-    { validitycheck(); return indexOf(item) >= 0; }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, return in the ref argument (a

-    /// binary copy of) the actual value found.

-    /// </summary>

-    /// <param name="item">The value to look for.</param>

-    /// <returns>True if the items is in this collection.</returns>

-    [Tested]

-    public virtual bool Find(ref T item)

-    {

-      validitycheck();

-

-      int i;

-

-      if ((i = indexOf(item)) >= 0)

-      {

-        item = array[offset + i];

-        return true;

-      }

-

-      return false;

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, update the item in the collection 

-    /// to with a binary copy of the supplied value. This will only update the first 

-    /// mathching item.

-    /// </summary>

-    /// <param name="item">Value to update.</param>

-    /// <returns>True if the item was found and hence updated.</returns>

-    [Tested]

-    public virtual bool Update(T item)

-    {

-      T olditem;

-      return Update(item, out olditem);

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item"></param>

-    /// <param name="olditem"></param>

-    /// <returns></returns>

-    public virtual bool Update(T item, out T olditem)

-    {

-      updatecheck();

-      int i;

-

-      if ((i = indexOf(item)) >= 0)

-      {

-        olditem = array[offset + i];

-        array[offset + i] = item;

-#if HASHINDEX

-        itemIndex.Update(new KeyValuePair<T, int>(item, offset + i));

-#endif

-        (underlying ?? this).raiseForUpdate(item, olditem);

-        return true;

-      }

-

-      olditem = default(T);

-      return false;

-    }

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, return in the ref argument (a

-    /// binary copy of) the actual value found. Else, add the item to the collection.

-    /// </summary>

-    /// <param name="item">The value to look for.</param>

-    /// <returns>True if the item was found (hence not added).</returns>

-    [Tested]

-    public virtual bool FindOrAdd(ref T item)

-    {

-      updatecheck();

-      if (Find(ref item))

-        return true;

-

-      Add(item);

-      return false;

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, update the item in the collection 

-    /// to with a binary copy of the supplied value. This will only update the first 

-    /// mathching item.

-    /// </summary>

-    /// <param name="item">Value to update.</param>

-    /// <returns>True if the item was found and hence updated.</returns>

-    [Tested]

-    public virtual bool UpdateOrAdd(T item)

-    {

-      updatecheck();

-      if (Update(item))

-        return true;

-

-      Add(item);

-      return false;

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item"></param>

-    /// <param name="olditem"></param>

-    /// <returns></returns>

-    public virtual bool UpdateOrAdd(T item, out T olditem)

-    {

-      updatecheck();

-      if (Update(item, out olditem))

-        return true;

-

-      Add(item);

-      olditem = default(T);

-      return false;

-    }

-

-    /// <summary>

-    /// Remove a particular item from this list. The item will be searched 

-    /// for from the end of the list if <code>FIFO == false</code> (the default), 

-    /// else from the start.

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    /// <returns>True if the item was found (and removed).</returns>

-    [Tested]

-    public virtual bool Remove(T item)

-    {

-      updatecheck();

-

-      int i = fIFO ? indexOf(item) : lastIndexOf(item);

-

-      if (i < 0)

-        return false;

-

-      T removeditem = removeAt(i);

-      (underlying ?? this).raiseForRemove(removeditem);

-      return true;

-    }

-

-

-    /// <summary>

-    /// Remove the first copy of a particular item from this collection if found.

-    /// If an item was removed, report a binary copy of the actual item removed in 

-    /// the argument. The item will be searched 

-    /// for from the end of the list if <code>FIFO == false</code> (the default), 

-    /// else from the start.

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    /// <param name="removeditem">The removed value.</param>

-    /// <returns>True if the item was found (and removed).</returns>

-    [Tested]

-    public virtual bool Remove(T item, out T removeditem)

-    {

-      updatecheck();

-

-      int i = fIFO ? indexOf(item) : lastIndexOf(item);

-

-      if (i < 0)

-      {

-        removeditem = default(T);

-        return false;

-      }

-

-      removeditem = removeAt(i);

-      (underlying ?? this).raiseForRemove(removeditem);

-      return true;

-    }

-

-

-    //TODO: remove from end or according to FIFO?

-    /// <summary>

-    /// Remove all items in another collection from this one, taking multiplicities into account.

-    /// Matching items will be removed from the front. Current implementation is not optimal.

-    /// </summary>

-    /// <typeparam name="U"></typeparam>

-    /// <param name="items">The items to remove.</param>

-    [Tested]

-    public virtual void RemoveAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      //TODO: reactivate the old code for small sizes

-      HashBag<T> toremove = new HashBag<T>(itemequalityComparer);

-      toremove.AddAll(items);

-      if (toremove.Count == 0)

-        return;

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-#endif

-      while (i < end)

-      {

-        T item;

-        //pass by a stretch of nodes

-        while (i < end && !toremove.Contains(item = array[i]))

-        {

-#if HASHINDEX

-          if (j < i)

-          {

-            p.Key = item;

-            p.Value = j;

-            itemIndex.Update(p);

-          }

-#endif

-          //if (j<i)

-          array[j] = item;

-          i++; j++;

-        }

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && toremove.Remove(item = array[i]))

-        {

-#if HASHINDEX

-          p.Key = item;

-          itemIndex.Remove(p);

-#endif

-          if (mustFire)

-            raiseHandler.Remove(item);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-#if HASHINDEX

-      reindex(j);

-#endif

-      if (mustFire)

-        raiseHandler.Raise();

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="predicate"></param>

-    void RemoveAll(Fun<T, bool> predicate)

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-#endif

-      while (i < end)

-      {

-        T item;

-        //pass by a stretch of nodes

-        while (i < end && !predicate(item = array[i]))

-        {

-          updatecheck();

-#if HASHINDEX

-          if (j < i)

-          {

-            p.Key = item;

-            p.Value = j;

-            itemIndex.Update(p);

-          }

-#endif

-          //if (j<i)

-          array[j] = item;

-          i++; j++;

-        }

-        updatecheck();

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && predicate(item = array[i]))

-        {

-          updatecheck();

-#if HASHINDEX

-          p.Key = item;

-          itemIndex.Remove(p);

-#endif

-          if (mustFire)

-            raiseHandler.Remove(item);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-        updatecheck();

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-#if HASHINDEX

-      reindex(j);

-#endif

-      if (mustFire)

-        raiseHandler.Raise();

-    }

-

-    /// <summary>

-    /// Remove all items from this collection, resetting internal array size.

-    /// </summary>

-    [Tested]

-    public override void Clear()

-    {

-      if (underlying == null)

-      {

-        updatecheck();

-        if (size == 0)

-          return;

-        int oldsize = size;

-        fixViewsBeforeRemove(0, size);

-#if HASHINDEX

-        itemIndex.Clear();

-#endif

-        array = new T[8];

-        size = 0;

-        (underlying ?? this).raiseForRemoveInterval(offset, oldsize);

-      }

-      else

-        RemoveInterval(0, size);

-    }

-

-    /// <summary>

-    /// Remove all items not in some other collection from this one, taking multiplicities into account.

-    /// Items are retained front first.  

-    /// </summary>

-    /// <typeparam name="U"></typeparam>

-    /// <param name="items">The items to retain.</param>

-    [Tested]

-    public virtual void RetainAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      HashBag<T> toretain = new HashBag<T>(itemequalityComparer);

-      toretain.AddAll(items);

-      if (toretain.Count == 0)

-      {

-        Clear();

-        return;

-      }

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-#endif

-      while (i < end)

-      {

-        T item;

-        //pass by a stretch of nodes

-        while (i < end && toretain.Remove(item = array[i]))

-        {

-#if HASHINDEX

-          if (j < i)

-          {

-            p.Key = item;

-            p.Value = j;

-            itemIndex.Update(p);

-          }

-#endif

-          //if (j<i)

-          array[j] = item;

-          i++; j++;

-        }

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && !toretain.Contains(item = array[i]))

-        {

-#if HASHINDEX

-          p.Key = item;

-          itemIndex.Remove(p);

-#endif

-          if (mustFire)

-            raiseHandler.Remove(item);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-#if HASHINDEX

-      reindex(j);

-#endif

-      raiseHandler.Raise();

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="predicate"></param>

-    void RetainAll(Fun<T, bool> predicate)

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-#endif

-      while (i < end)

-      {

-        T item;

-        //pass by a stretch of nodes

-        while (i < end && predicate(item = array[i]))

-        {

-          updatecheck();

-#if HASHINDEX

-          if (j < i)

-          {

-            p.Key = item;

-            p.Value = j;

-            itemIndex.Update(p);

-          }

-#endif

-          //if (j<i)

-          array[j] = item;

-          i++; j++;

-        }

-        updatecheck();

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && !predicate(item = array[i]))

-        {

-          updatecheck();

-#if HASHINDEX

-          p.Key = item;

-          itemIndex.Remove(p);

-#endif

-          if (mustFire)

-            raiseHandler.Remove(item);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-        updatecheck();

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-#if HASHINDEX

-      reindex(j);

-#endif

-      raiseHandler.Raise();

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains all the values in another collection,

-    /// taking multiplicities into account.

-    /// Current implementation is not optimal.

-    /// </summary>

-    /// <param name="items">The </param>

-    /// <typeparam name="U"></typeparam>

-    /// <returns>True if all values in <code>items</code>is in this collection.</returns>

-    [Tested]

-    public virtual bool ContainsAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      validitycheck();

-#if HASHINDEX

-      foreach (T item in items)

-        if (indexOf(item) < 0)

-          return false;

-

-      return true;

-#else

-      //TODO: use aux hash bag to obtain linear time procedure

-      HashBag<T> tomatch = new HashBag<T>(itemequalityComparer);

-      tomatch.AddAll(items);

-      if (tomatch.Count == 0)

-        return true;

-      for (int i = offset, end = offset + size; i < end; i++)

-      {

-        tomatch.Remove(array[i]);

-        if (tomatch.Count == 0)

-          return true;

-      }

-      return false;

-#endif

-    }

-

-

-    /// <summary>

-    /// Count the number of items of the collection equal to a particular value.

-    /// Returns 0 if and only if the value is not in the collection.

-    /// </summary>

-    /// <param name="item">The value to count.</param>

-    /// <returns>The number of copies found.</returns>

-    [Tested]

-    public virtual int ContainsCount(T item)

-    {

-      validitycheck();

-#if HASHINDEX

-      return indexOf(item) >= 0 ? 1 : 0;

-#else

-      int count = 0;

-      for (int i = 0; i < size; i++)

-        if (equals(item, array[offset + i]))

-          count++;

-      return count;

-#endif

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public virtual ICollectionValue<T> UniqueItems()

-    {

-#if HASHINDEX

-      return this;

-#else

-      HashBag<T> hashbag = new HashBag<T>(itemequalityComparer);

-      hashbag.AddAll(this);

-      return hashbag.UniqueItems();

-#endif

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public virtual ICollectionValue<KeyValuePair<T, int>> ItemMultiplicities()

-    {

-#if HASHINDEX

-      return new MultiplicityOne<T>(this);

-#else

-      HashBag<T> hashbag = new HashBag<T>(itemequalityComparer);

-      hashbag.AddAll(this);

-      return hashbag.ItemMultiplicities();

-#endif

-    }

-

-

-

-

-

-    /// <summary>

-    /// Remove all items equal to a given one.

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    [Tested]

-    public virtual void RemoveAllCopies(T item)

-    {

-#if HASHINDEX

-      Remove(item);

-#else

-      updatecheck();

-      if (size == 0)

-        return;

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-      while (i < end)

-      {

-        //pass by a stretch of nodes

-        while (i < end && !equals(item, array[i]))

-          array[j++] = array[i++];

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && equals(item, array[i]))

-        {

-          if (mustFire)

-            raiseHandler.Remove(array[i]);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-      raiseHandler.Raise();

-#endif

-    }

-

-

-    //TODO: check views

-    /// <summary>

-    /// Check the integrity of the internal data structures of this array list.

-    /// </summary>

-    /// <returns>True if check does not fail.</returns>

-    [Tested]

-    public override bool Check()

-    {

-      bool retval = true;

-

-      if (underlyingsize > array.Length)

-      {

-        Console.WriteLine("underlyingsize ({0}) > array.Length ({1})", size, array.Length);

-        return false;

-      }

-

-      if (offset + size > underlyingsize)

-      {

-        Console.WriteLine("offset({0})+size({1}) > underlyingsize ({2})", offset, size, underlyingsize);

-        return false;

-      }

-

-      if (offset < 0)

-      {

-        Console.WriteLine("offset({0}) < 0", offset);

-        return false;

-      }

-

-      for (int i = 0; i < underlyingsize; i++)

-      {

-        if ((object)(array[i]) == null)

-        {

-          Console.WriteLine("Bad element: null at (base)index {0}", i);

-          retval = false;

-        }

-      }

-

-      for (int i = underlyingsize, length = array.Length; i < length; i++)

-      {

-        if (!equals(array[i], default(T)))

-        {

-          Console.WriteLine("Bad element: != default(T) at (base)index {0}", i);

-          retval = false;

-        }

-      }

-

-      {

-        ArrayList<T> u = underlying ?? this;

-        if (u.views != null)

-          foreach (ArrayList<T> v in u.views)

-          {

-            if (u.array != v.array)

-            {

-              Console.WriteLine("View from {0} of length has different base array than the underlying list", v.offset, v.size);

-              retval = false;

-            }

-          }

-      }

-

-

-#if HASHINDEX

-      if (underlyingsize != itemIndex.Count)

-      {

-        Console.WriteLine("size ({0})!= index.Count ({1})", size, itemIndex.Count);

-        retval = false;

-      }

-

-      for (int i = 0; i < underlyingsize; i++)

-      {

-        KeyValuePair<T, int> p = new KeyValuePair<T, int>(array[i]);

-

-        if (!itemIndex.Find(ref p))

-        {

-          Console.WriteLine("Item {1} at {0} not in hashindex", i, array[i]);

-          retval = false;

-        }

-

-        if (p.Value != i)

-        {

-          Console.WriteLine("Item {1} at {0} has hashindex {2}", i, array[i], p.Value);

-          retval = false;

-        }

-      }

-#endif

-      return retval;

-    }

-

-    #endregion

-

-    #region IExtensible<T> Members

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value>True, indicating array list has bag semantics.</value>

-    [Tested]

-    public virtual bool AllowsDuplicates

-    {

-      [Tested]

-      get

-      {

-#if HASHINDEX

-        return false;

-#else

-        return true;

-#endif

-      }

-    }

-

-    /// <summary>

-    /// By convention this is true for any collection with set semantics.

-    /// </summary>

-    /// <value>True if only one representative of a group of equal items 

-    /// is kept in the collection together with the total count.</value>

-    public virtual bool DuplicatesByCounting

-    {

-      get

-      {

-#if HASHINDEX

-        return true;

-#else

-        return false;

-#endif

-      }

-    }

-

-    /// <summary>

-    /// Add an item to end of this list.

-    /// </summary>

-    /// <param name="item">The item to add.</param>

-    /// <returns>True</returns>

-    [Tested]

-    public virtual bool Add(T item)

-    {

-      updatecheck();

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, size + offset);

-      if (itemIndex.FindOrAdd(ref p))

-        return false;

-#endif

-      baseinsert(size, item);

-#if HASHINDEX

-      reindex(size + offset);

-#endif

-      (underlying ?? this).raiseForAdd(item);

-      return true;

-    }

-

-

-    /// <summary>

-    /// Add the elements from another collection to this collection.

-    /// </summary>

-    /// <typeparam name="U"></typeparam>

-    /// <param name="items"></param>

-    [Tested]

-    public virtual void AddAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      updatecheck();

-      int toadd = EnumerableBase<U>.countItems(items);

-      if (toadd == 0)

-        return;

-

-      if (toadd + underlyingsize > array.Length)

-        expand(toadd + underlyingsize, underlyingsize);

-

-      int i = size + offset;

-      if (underlyingsize > i)

-        Array.Copy(array, i, array, i + toadd, underlyingsize - i);

-      try

-      {

-        foreach (T item in items)

-        {

-#if HASHINDEX

-          KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, i);

-          if (itemIndex.FindOrAdd(ref p))

-            continue;

-#endif

-          array[i++] = item;

-        }

-      }

-      finally

-      {

-        int added = i - size - offset;

-        if (added < toadd)

-        {

-          Array.Copy(array, size + offset + toadd, array, i, underlyingsize - size - offset);

-          Array.Clear(array, underlyingsize + added, toadd - added);

-        }

-        if (added > 0)

-        {

-          addtosize(added);

-#if HASHINDEX

-          reindex(i);

-#endif

-          fixViewsAfterInsert(added, i - added);

-          (underlying ?? this).raiseForAddAll(i - added, added);

-        }

-      }

-    }

-    private void raiseForAddAll(int start, int added)

-    {

-      if ((ActiveEvents & EventTypeEnum.Added) != 0)

-        for (int i = start, end = start + added; i < end; i++)

-          raiseItemsAdded(array[i], 1);

-      raiseCollectionChanged();

-    }

-

-    #endregion

-

-    #region IDirectedEnumerable<T> Members

-

-    /// <summary>

-    /// Create a collection containing the same items as this collection, but

-    /// whose enumerator will enumerate the items backwards. The new collection

-    /// will become invalid if the original is modified. Method typicaly used as in

-    /// <code>foreach (T x in coll.Backwards()) {...}</code>

-    /// </summary>

-    /// <returns>The backwards collection.</returns>

-    [Tested]

-    IDirectedEnumerable<T> IDirectedEnumerable<T>.Backwards() { return Backwards(); }

-

-    #endregion

-

-    #region ICollectionValue<T> Members

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value>The number of items in this collection</value>

-    [Tested]

-    public override int Count { [Tested]get { validitycheck(); return size; } }

-    #endregion

-

-    #region IEnumerable<T> Members

-    //TODO: make tests of all calls on a disposed view throws the right exception! (Which should be C5.InvalidListViewException)

-    /// <summary>

-    /// Create an enumerator for the collection

-    /// </summary>

-    /// <returns>The enumerator</returns>

-    [Tested]

-    public override SCG.IEnumerator<T> GetEnumerator()

-    {

-      validitycheck();

-      return base.GetEnumerator();

-    }

-    #endregion

-

-#if HASHINDEX

-#else

-    #region IStack<T> Members

-

-    /// <summary>

-    /// Push an item to the top of the stack.

-    /// </summary>

-    /// <param name="item">The item</param>

-    [Tested]

-    public virtual void Push(T item)

-    {

-      InsertLast(item);

-    }

-

-    /// <summary>

-    /// Pop the item at the top of the stack from the stack.

-    /// </summary>

-    /// <returns>The popped item.</returns>

-    [Tested]

-    public virtual T Pop()

-    {

-      return RemoveLast();

-    }

-

-    #endregion

-

-    #region IQueue<T> Members

-

-    /// <summary>

-    /// Enqueue an item at the back of the queue. 

-    /// </summary>

-    /// <param name="item">The item</param>

-    [Tested]

-    public virtual void Enqueue(T item)

-    {

-      InsertLast(item);

-    }

-

-    /// <summary>

-    /// Dequeue an item from the front of the queue.

-    /// </summary>

-    /// <returns>The item</returns>

-    [Tested]

-    public virtual T Dequeue()

-    {

-      return RemoveFirst();

-    }

-

-    #endregion

-#endif

-    #region IDisposable Members

-

-    /// <summary>

-    /// Invalidate this list. If a view, just invalidate the view. 

-    /// If not a view, invalidate the list and all views on it.

-    /// </summary>

-    public virtual void Dispose()

-    {

-      Dispose(false);

-    }

-

-    void Dispose(bool disposingUnderlying)

-    {

-      if (isValid)

-      {

-        if (underlying != null)

-        {

-          isValid = false;

-          if (!disposingUnderlying && views != null)

-            views.Remove(myWeakReference);

-          underlying = null;

-          views = null;

-          myWeakReference = null;

-        }

-        else

-        {

-          //isValid = false;

-          if (views != null)

-            foreach (ArrayList<T> view in views)

-              view.Dispose(true);

-          Clear();

-        }

-      }

-    }

-

-    #endregion

-

-    #region ICloneable Members

-

-    /// <summary>

-    /// Make a shallow copy of this ArrayList.

-    /// </summary>

-    /// <returns></returns>

-    public virtual object Clone()

-    {

-      ArrayList<T> clone = new ArrayList<T>(size, itemequalityComparer);

-      clone.AddAll(this);

-      return clone;

-    }

-

-    #endregion

-

-    #region ISerializable Members

-    /*

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="info"></param>

-    /// <param name="context"></param>

-    public ArrayList(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) :

-      this(info.GetInt32("sz"),(SCG.IEqualityComparer<T>)(info.GetValue("eq",typeof(SCG.IEqualityComparer<T>))))

-    {

-      size = info.GetInt32("sz");

-      for (int i = 0; i < size; i++)

-      {

-        array[i] = (T)(info.GetValue("elem" + i,typeof(T)));

-      }

-#if HASHINDEX

-      reindex(0);

-#endif      

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="info"></param>

-    /// <param name="context"></param>

-    public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)

-    {

-      info.AddValue("sz", size);

-      info.AddValue("eq", EqualityComparer);

-      for (int i = 0; i < size; i++)

-			{

-        info.AddValue("elem" + i, array[i + offset]);

-      }

-    }

-*/

-    #endregion

-

-    #region System.Collections.Generic.IList<T> Members

-

-    void System.Collections.Generic.IList<T>.RemoveAt(int index)

-    {

-      RemoveAt(index);

-    }

-

-    void System.Collections.Generic.ICollection<T>.Add(T item)

-    {

-      Add(item);

-    }

-

-    #endregion

-

-    #region System.Collections.ICollection Members

-

-    bool System.Collections.ICollection.IsSynchronized

-    {

-      get { return false; }

-    }

-

-    [Obsolete]

-    Object System.Collections.ICollection.SyncRoot

-    {

-      get { return underlying != null ? ((System.Collections.ICollection)underlying).SyncRoot : array; }

-    }

-

-    void System.Collections.ICollection.CopyTo(Array arr, int index)

-    {

-      if (index < 0 || index + Count > arr.Length)

-        throw new ArgumentOutOfRangeException();

-

-      foreach (T item in this)

-        arr.SetValue(item, index++);

-    }

-

-    #endregion

-

-    #region System.Collections.IList Members

-

-    Object System.Collections.IList.this[int index]

-    {

-      get { return this[index]; }

-      set { this[index] = (T)value; }

-    }

-

-    int System.Collections.IList.Add(Object o)

-    {

-      bool added = Add((T)o);

-      // What position to report if item not added? SC.IList.Add doesn't say

-      return added ? Count - 1 : -1;

-    }

-

-    bool System.Collections.IList.Contains(Object o)

-    {

-      return Contains((T)o);

-    }

-

-    int System.Collections.IList.IndexOf(Object o)

-    {

-      return Math.Max(-1, IndexOf((T)o));

-    }

-

-    void System.Collections.IList.Insert(int index, Object o)

-    {

-      Insert(index, (T)o);

-    }

-

-    void System.Collections.IList.Remove(Object o)

-    {

-      Remove((T)o);

-    }

-

-    void System.Collections.IList.RemoveAt(int index)

-    {

-      RemoveAt(index);

-    }

-

-    #endregion

-  }

-}

+
+/*
+ Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+ 
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+ 
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+*/
+
+#define HASHINDEXnot
+
+using System;
+using System.Diagnostics;
+using SCG = System.Collections.Generic;
+namespace C5
+{
+  /// <summary>
+  /// A list collection based on a plain dynamic array data structure.
+  /// Expansion of the internal array is performed by doubling on demand. 
+  /// The internal array is only shrinked by the Clear method. 
+  ///
+  /// <i>When the FIFO property is set to false this class works fine as a stack of T.
+  /// When the FIFO property is set to true the class will function as a (FIFO) queue
+  /// but very inefficiently, use a LinkedList (<see cref="T:C5.LinkedList`1"/>) instead.</i>
+  /// </summary>
+  [Serializable]
+  public class ArrayList<T> : ArrayBase<T>, IList<T>, SCG.IList<T>
+#if HASHINDEX
+#else
+, IStack<T>, IQueue<T>
+#endif
+  {
+    #region Fields
+
+    /// <summary>
+    /// Has this list or view not been invalidated by some operation (by someone calling Dispose())
+    /// </summary>
+    bool isValid = true;
+
+    //TODO: wonder if we should save some memory on none-view situations by 
+    //      putting these three fields into a single ref field?
+    /// <summary>
+    /// The underlying list if we are a view, null else.
+    /// </summary>
+    ArrayList<T> underlying;
+    WeakViewList<ArrayList<T>> views;
+    WeakViewList<ArrayList<T>>.Node myWeakReference;
+
+    /// <summary>
+    /// The size of the underlying list.
+    /// </summary>
+    int underlyingsize { get { return (underlying ?? this).size; } }
+
+    /// <summary>
+    /// The underlying field of the FIFO property
+    /// </summary>
+    bool fIFO = false;
+
+#if HASHINDEX
+    HashSet<KeyValuePair<T, int>> itemIndex;
+#endif
+    #endregion
+    #region Events
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public override EventTypeEnum ListenableEvents { get { return underlying == null ? EventTypeEnum.All : EventTypeEnum.None; } }
+
+    /*
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event CollectionChangedHandler<T> CollectionChanged
+        {
+          add
+          {
+            if (underlying == null)
+              base.CollectionChanged += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.CollectionChanged -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event CollectionClearedHandler<T> CollectionCleared
+        {
+          add
+          {
+            if (underlying == null)
+              base.CollectionCleared += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.CollectionCleared -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event ItemsAddedHandler<T> ItemsAdded
+        {
+          add
+          {
+            if (underlying == null)
+              base.ItemsAdded += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.ItemsAdded -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event ItemInsertedHandler<T> ItemInserted
+        {
+          add
+          {
+            if (underlying == null)
+              base.ItemInserted += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.ItemInserted -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event ItemsRemovedHandler<T> ItemsRemoved
+        {
+          add
+          {
+            if (underlying == null)
+              base.ItemsRemoved += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.ItemsRemoved -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event ItemRemovedAtHandler<T> ItemRemovedAt
+        {
+          add
+          {
+            if (underlying == null)
+              base.ItemRemovedAt += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.ItemRemovedAt -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+          */
+
+    #endregion
+    #region Util
+
+    bool equals(T i1, T i2) { return itemequalityComparer.Equals(i1, i2); }
+
+    /// <summary>
+    /// Increment or decrement the private size fields
+    /// </summary>
+    /// <param name="delta">Increment (with sign)</param>
+    void addtosize(int delta)
+    {
+      size += delta;
+      if (underlying != null)
+        underlying.size += delta;
+    }
+
+    #region Array handling
+    /// <summary>
+    /// Double the size of the internal array.
+    /// </summary>
+    protected override void expand()
+    { expand(2 * array.Length, underlyingsize); }
+
+
+    /// <summary>
+    /// Expand the internal array, resetting the index of the first unused element.
+    /// </summary>
+    /// <param name="newcapacity">The new capacity (will be rouded upwards to a power of 2).</param>
+    /// <param name="newsize">The new count of </param>
+    protected override void expand(int newcapacity, int newsize)
+    {
+      if (underlying != null)
+        underlying.expand(newcapacity, newsize);
+      else
+      {
+        base.expand(newcapacity, newsize);
+        if (views != null)
+          foreach (ArrayList<T> v in views)
+            v.array = array;
+      }
+    }
+
+    #endregion
+
+    #region Checks
+    /// <summary>
+    /// Check if it is valid to perform updates and increment stamp if so.
+    /// </summary>
+    /// <exception cref="ViewDisposedException"> If check fails by this list being a disposed view.</exception>
+    /// <exception cref="ReadOnlyCollectionException"> If check fails by this being a read only list.</exception>
+    protected override void updatecheck()
+    {
+      validitycheck();
+      base.updatecheck();
+      if (underlying != null)
+        underlying.stamp++;
+    }
+
+
+    /// <summary>
+    /// Check if we are a view that the underlying list has only been updated through us.
+    /// <para>This method should be called from enumerators etc to guard against 
+    /// modification of the base collection.</para>
+    /// </summary>
+    /// <exception cref="ViewDisposedException"> if check fails.</exception>
+    void validitycheck()
+    {
+      if (!isValid)
+        throw new ViewDisposedException();
+    }
+
+
+    /// <summary>
+    /// Check that the list has not been updated since a particular time.
+    /// <para>To be used by enumerators and range </para>
+    /// </summary>
+    /// <exception cref="ViewDisposedException"> If check fails by this list being a disposed view.</exception>
+    /// <exception cref="CollectionModifiedException">If the list *has* beeen updated since that  time..</exception>
+    /// <param name="stamp">The stamp indicating the time.</param>
+    protected override void modifycheck(int stamp)
+    {
+      validitycheck();
+      if (this.stamp != stamp)
+        throw new CollectionModifiedException();
+    }
+
+    #endregion
+
+    #region Searching
+
+    /// <summary>
+    /// Internal version of IndexOf without modification checks.
+    /// </summary>
+    /// <param name="item">Item to look for</param>
+    /// <returns>The index of first occurrence</returns>
+    int indexOf(T item)
+    {
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item);
+      if (itemIndex.Find(ref p) && p.Value >= offset && p.Value < offset + size)
+        return p.Value - offset;
+#else
+      for (int i = 0; i < size; i++)
+        if (equals(item, array[offset + i]))
+          return i;
+#endif
+      return ~size;
+    }
+
+    /// <summary>
+    /// Internal version of LastIndexOf without modification checks.
+    /// </summary>
+    /// <param name="item">Item to look for</param>
+    /// <returns>The index of last occurrence</returns>
+    int lastIndexOf(T item)
+    {
+#if HASHINDEX
+      return indexOf(item);
+#else
+      for (int i = size - 1; i >= 0; i--)
+        if (equals(item, array[offset + i]))
+          return i;
+      return ~size;
+#endif
+    }
+    #endregion
+
+    #region Inserting
+
+#if HASHINDEX
+    /// <summary>
+    /// Internal version of Insert with no modification checks.
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException"> if item already in list.</exception>
+    /// <param name="i">Index to insert at</param>
+    /// <param name="item">Item to insert</param>
+#else
+    /// <summary>
+    /// Internal version of Insert with no modification checks.
+    /// </summary>
+    /// <param name="i">Index to insert at</param>
+    /// <param name="item">Item to insert</param>
+#endif
+    protected override void insert(int i, T item)
+    {
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, offset + i);
+      if (itemIndex.FindOrAdd(ref p))
+        throw new DuplicateNotAllowedException("Item already in indexed list: " + item);
+#endif
+      baseinsert(i, item);
+#if HASHINDEX
+      reindex(i + offset + 1);
+#endif
+    }
+
+    private void baseinsert(int i, T item)
+    {
+      if (underlyingsize == array.Length)
+        expand();
+      i += offset;
+      if (i < underlyingsize)
+        Array.Copy(array, i, array, i + 1, underlyingsize - i);
+      array[i] = item;
+      addtosize(1);
+      fixViewsAfterInsert(1, i);
+    }
+    #endregion
+
+    #region Removing
+
+    /// <summary>
+    /// Internal version of RemoveAt with no modification checks.
+    /// </summary>
+    /// <param name="i">Index to remove at</param>
+    /// <returns>The removed item</returns>
+    T removeAt(int i)
+    {
+      i += offset;
+      fixViewsBeforeSingleRemove(i);
+      T retval = array[i];
+      addtosize(-1);
+      if (underlyingsize > i)
+        Array.Copy(array, i + 1, array, i, underlyingsize - i);
+      array[underlyingsize] = default(T);
+#if HASHINDEX
+      itemIndex.Remove(new KeyValuePair<T, int>(retval));
+      reindex(i);
+#endif
+      return retval;
+    }
+    #endregion
+
+    #region Indexing
+
+#if HASHINDEX
+    private void reindex(int start) { reindex(start, underlyingsize); }
+
+    private void reindex(int start, int end)
+    {
+      for (int j = start; j < end; j++)
+        itemIndex.UpdateOrAdd(new KeyValuePair<T, int>(array[j], j));
+    }
+#endif
+    #endregion
+
+    #region fixView utilities
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="added">The actual number of inserted nodes</param>
+    /// <param name="realInsertionIndex"></param>
+    void fixViewsAfterInsert(int added, int realInsertionIndex)
+    {
+      if (views != null)
+        foreach (ArrayList<T> view in views)
+        {
+          if (view != this)
+          {
+            if (view.offset < realInsertionIndex && view.offset + view.size > realInsertionIndex)
+              view.size += added;
+            if (view.offset > realInsertionIndex || (view.offset == realInsertionIndex && view.size > 0))
+              view.offset += added;
+          }
+        }
+    }
+
+    void fixViewsBeforeSingleRemove(int realRemovalIndex)
+    {
+      if (views != null)
+        foreach (ArrayList<T> view in views)
+        {
+          if (view != this)
+          {
+            if (view.offset <= realRemovalIndex && view.offset + view.size > realRemovalIndex)
+              view.size--;
+            if (view.offset > realRemovalIndex)
+              view.offset--;
+          }
+        }
+    }
+
+    /// <summary>
+    /// Fix offsets and sizes of other views before removing an interval from this 
+    /// </summary>
+    /// <param name="start">the start of the interval relative to the array/underlying</param>
+    /// <param name="count"></param>
+    void fixViewsBeforeRemove(int start, int count)
+    {
+      int clearend = start + count - 1;
+      if (views != null)
+        foreach (ArrayList<T> view in views)
+        {
+          if (view == this)
+            continue;
+          int viewoffset = view.offset, viewend = viewoffset + view.size - 1;
+          if (start < viewoffset)
+          {
+            if (clearend < viewoffset)
+              view.offset = viewoffset - count;
+            else
+            {
+              view.offset = start;
+              view.size = clearend < viewend ? viewend - clearend : 0;
+            }
+          }
+          else if (start <= viewend)
+            view.size = clearend <= viewend ? view.size - count : start - viewoffset;
+        }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="otherOffset"></param>
+    /// <param name="otherSize"></param>
+    /// <returns>The position of View(otherOffset, otherSize) wrt. this view</returns>
+    MutualViewPosition viewPosition(int otherOffset, int otherSize)
+    {
+      int end = offset + size, otherEnd = otherOffset + otherSize;
+      if (otherOffset >= end || otherEnd <= offset)
+        return MutualViewPosition.NonOverlapping;
+      if (size == 0 || (otherOffset <= offset && end <= otherEnd))
+        return MutualViewPosition.Contains;
+      if (otherSize == 0 || (offset <= otherOffset && otherEnd <= end))
+        return MutualViewPosition.ContainedIn;
+      return MutualViewPosition.Overlapping;
+    }
+
+    //TODO: make version that fits the new, more forgiving rules for disposing
+    void disposeOverlappingViews(bool reverse)
+    {
+      if (views != null)
+        foreach (ArrayList<T> view in views)
+        {
+          if (view != this)
+          {
+            switch (viewPosition(view.offset, view.size))
+            {
+              case MutualViewPosition.ContainedIn:
+                if (reverse)
+                  view.offset = 2 * offset + size - view.size - view.offset;
+                else
+                  view.Dispose();
+                break;
+              case MutualViewPosition.Overlapping:
+                view.Dispose();
+                break;
+              case MutualViewPosition.Contains:
+              case MutualViewPosition.NonOverlapping:
+                break;
+            }
+          }
+        }
+    }
+    #endregion
+
+    #endregion
+
+    #region Position, PositionComparer and ViewHandler nested types
+    class PositionComparer : SCG.IComparer<Position>
+    {
+      public int Compare(Position a, Position b)
+      {
+        return a.index.CompareTo(b.index);
+      }
+    }
+    /// <summary>
+    /// During RemoveAll, we need to cache the original endpoint indices of views (??? also for ArrayList?)
+    /// </summary>
+    struct Position
+    {
+      public readonly ArrayList<T> view;
+      public readonly int index;
+      public Position(ArrayList<T> view, bool left)
+      {
+        this.view = view;
+        index = left ? view.offset : view.offset + view.size - 1;
+      }
+      public Position(int index) { this.index = index; view = null; }
+    }
+
+    /// <summary>
+    /// Handle the update of (other) views during a multi-remove operation.
+    /// </summary>
+    struct ViewHandler
+    {
+      ArrayList<Position> leftEnds;
+      ArrayList<Position> rightEnds;
+      int leftEndIndex, rightEndIndex;
+      internal readonly int viewCount;
+      internal ViewHandler(ArrayList<T> list)
+      {
+        leftEndIndex = rightEndIndex = viewCount = 0;
+        leftEnds = rightEnds = null;
+        if (list.views != null)
+          foreach (ArrayList<T> v in list.views)
+            if (v != list)
+            {
+              if (leftEnds == null)
+              {
+                leftEnds = new ArrayList<Position>();
+                rightEnds = new ArrayList<Position>();
+              }
+              leftEnds.Add(new Position(v, true));
+              rightEnds.Add(new Position(v, false));
+            }
+        if (leftEnds == null)
+          return;
+        viewCount = leftEnds.Count;
+        leftEnds.Sort(new PositionComparer());
+        rightEnds.Sort(new PositionComparer());
+      }
+      /// <summary>
+      /// This is to be called with realindex pointing to the first node to be removed after a (stretch of) node that was not removed
+      /// </summary>
+      /// <param name="removed"></param>
+      /// <param name="realindex"></param>
+      internal void skipEndpoints(int removed, int realindex)
+      {
+        if (viewCount > 0)
+        {
+          Position endpoint;
+          while (leftEndIndex < viewCount && (endpoint = leftEnds[leftEndIndex]).index <= realindex)
+          {
+            ArrayList<T> view = endpoint.view;
+            view.offset = view.offset - removed;
+            view.size += removed;
+            leftEndIndex++;
+          }
+          while (rightEndIndex < viewCount && (endpoint = rightEnds[rightEndIndex]).index < realindex)
+          {
+            endpoint.view.size -= removed;
+            rightEndIndex++;
+          }
+        }
+      }
+      internal void updateViewSizesAndCounts(int removed, int realindex)
+      {
+        if (viewCount > 0)
+        {
+          Position endpoint;
+          while (leftEndIndex < viewCount && (endpoint = leftEnds[leftEndIndex]).index <= realindex)
+          {
+            ArrayList<T> view = endpoint.view;
+            view.offset = view.Offset - removed;
+            view.size += removed;
+            leftEndIndex++;
+          }
+          while (rightEndIndex < viewCount && (endpoint = rightEnds[rightEndIndex]).index < realindex)
+          {
+            endpoint.view.size -= removed;
+            rightEndIndex++;
+          }
+        }
+      }
+    }
+    #endregion
+
+    #region Constructors
+    /// <summary>
+    /// Create an array list with default item equalityComparer and initial capacity 8 items.
+    /// </summary>
+    public ArrayList() : this(8) { }
+
+
+    /// <summary>
+    /// Create an array list with external item equalityComparer and initial capacity 8 items.
+    /// </summary>
+    /// <param name="itemequalityComparer">The external item equalityComparer</param>
+    public ArrayList(SCG.IEqualityComparer<T> itemequalityComparer) : this(8, itemequalityComparer) { }
+
+
+    /// <summary>
+    /// Create an array list with default item equalityComparer and prescribed initial capacity.
+    /// </summary>
+    /// <param name="capacity">The prescribed capacity</param>
+    public ArrayList(int capacity) : this(capacity, EqualityComparer<T>.Default) { }
+
+
+    /// <summary>
+    /// Create an array list with external item equalityComparer and prescribed initial capacity.
+    /// </summary>
+    /// <param name="capacity">The prescribed capacity</param>
+    /// <param name="itemequalityComparer">The external item equalityComparer</param>
+    public ArrayList(int capacity, SCG.IEqualityComparer<T> itemequalityComparer)
+      : base(capacity, itemequalityComparer)
+    {
+#if HASHINDEX
+      itemIndex = new HashSet<KeyValuePair<T, int>>(new KeyValuePairEqualityComparer<T, int>(itemequalityComparer));
+#endif
+    }
+
+    #endregion
+
+    #region IList<T> Members
+
+    /// <summary>
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <value>The first item in this list.</value>
+    [Tested]
+    public virtual T First
+    {
+      [Tested]
+      get
+      {
+        validitycheck();
+        if (size == 0)
+          throw new NoSuchItemException();
+
+        return array[offset];
+      }
+    }
+
+
+    /// <summary>
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <value>The last item in this list.</value>
+    [Tested]
+    public virtual T Last
+    {
+      [Tested]
+      get
+      {
+        validitycheck();
+        if (size == 0)
+          throw new NoSuchItemException();
+
+        return array[offset + size - 1];
+      }
+    }
+
+
+    /// <summary>
+    /// Since <code>Add(T item)</code> always add at the end of the list,
+    /// this describes if list has FIFO or LIFO semantics.
+    /// </summary>
+    /// <value>True if the <code>Remove()</code> operation removes from the
+    /// start of the list, false if it removes from the end. The default for a new array list is false.</value>
+    [Tested]
+    public virtual bool FIFO
+    {
+      [Tested]
+      get { validitycheck(); return fIFO; }
+      [Tested]
+      set { updatecheck(); fIFO = value; }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public virtual bool IsFixedSize
+    {
+      get { validitycheck(); return false; }
+    }
+
+
+#if HASHINDEX
+    /// <summary>
+    /// On this list, this indexer is read/write.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt;= the size of the collection.</exception>
+    /// <exception cref="DuplicateNotAllowedException"> By the get operation
+    /// if the item already is present somewhere else in the list.</exception>
+    /// <value>The index'th item of this list.</value>
+    /// <param name="index">The index of the item to fetch or store.</param>
+#else
+    /// <summary>
+    /// On this list, this indexer is read/write.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt;= the size of the collection.</exception>
+    /// <value>The index'th item of this list.</value>
+    /// <param name="index">The index of the item to fetch or store.</param>
+#endif
+    [Tested]
+    public virtual T this[int index]
+    {
+      [Tested]
+      get
+      {
+        validitycheck();
+        if (index < 0 || index >= size)
+          throw new IndexOutOfRangeException();
+
+        return array[offset + index];
+      }
+      [Tested]
+      set
+      {
+        updatecheck();
+        if (index < 0 || index >= size)
+          throw new IndexOutOfRangeException();
+        index += offset;
+        T item = array[index];
+#if HASHINDEX
+        KeyValuePair<T, int> p = new KeyValuePair<T, int>(value, index);
+        if (itemequalityComparer.Equals(value, item))
+        {
+          array[index] = value;
+          itemIndex.Update(p);
+        }
+        else if (!itemIndex.FindOrAdd(ref p))
+        {
+          itemIndex.Remove(new KeyValuePair<T, int>(item));
+          array[index] = value;
+        }
+        else
+          throw new DuplicateNotAllowedException("Item already in indexed list");
+#else
+        array[index] = value;
+#endif
+        (underlying ?? this).raiseForSetThis(index, value, item);
+      }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public virtual Speed IndexingSpeed { get { return Speed.Constant; } }
+
+#if HASHINDEX
+    /// <summary>
+    /// Insert an item at a specific index location in this list. 
+    ///</summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt; the size of the collection. </exception>
+    /// <exception cref="DuplicateNotAllowedException"> 
+    /// If the item is already present in the list.</exception>
+    /// <param name="index">The index at which to insert.</param>
+    /// <param name="item">The item to insert.</param>
+#else
+    /// <summary>
+    /// Insert an item at a specific index location in this list. 
+    ///</summary>
+    /// <exception cref="IndexOutOfRangeException"> if i is negative or
+    /// &gt; the size of the collection. </exception>
+    /// <param name="index">The index at which to insert.</param>
+    /// <param name="item">The item to insert.</param>
+#endif
+    [Tested]
+    public virtual void Insert(int index, T item)
+    {
+      updatecheck();
+      if (index < 0 || index > size)
+        throw new IndexOutOfRangeException();
+
+      insert(index, item);
+      (underlying ?? this).raiseForInsert(index + offset, item);
+    }
+
+    /// <summary>
+    /// Insert an item at the end of a compatible view, used as a pointer.
+    /// <para>The <code>pointer</code> must be a view on the same list as
+    /// <code>this</code> and the endpoitn of <code>pointer</code> must be
+    /// a valid insertion point of <code>this</code></para>
+    /// </summary>
+    /// <exception cref="IncompatibleViewException">If <code>pointer</code> 
+    /// is not a view on or the same list as <code>this</code></exception>
+    /// <exception cref="IndexOutOfRangeException"><b>??????</b> if the endpoint of 
+    ///  <code>pointer</code> is not inside <code>this</code></exception>
+    /// <exception cref="DuplicateNotAllowedException"> if the list has
+    /// <code>AllowsDuplicates==false</code> and the item is 
+    /// already in the list.</exception>
+    /// <param name="pointer"></param>
+    /// <param name="item"></param>
+    public void Insert(IList<T> pointer, T item)
+    {
+      if ((pointer == null) || ((pointer.Underlying ?? pointer) != (underlying ?? this)))
+        throw new IncompatibleViewException();
+      Insert(pointer.Offset + pointer.Count - Offset, item);
+    }
+
+#if HASHINDEX
+    /// <summary>
+    /// Insert into this list all items from an enumerable collection starting 
+    /// at a particular index.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt; the size of the collection.</exception>
+    /// <exception cref="DuplicateNotAllowedException"> If <code>items</code> 
+    /// contains duplicates or some item already  present in the list.</exception>
+    /// <param name="index">Index to start inserting at</param>
+    /// <param name="items">Items to insert</param>
+#else
+    /// <summary>
+    /// Insert into this list all items from an enumerable collection starting 
+    /// at a particular index.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt; the size of the collection.</exception>
+    /// <param name="index">Index to start inserting at</param>
+    /// <param name="items">Items to insert</param>
+    /// <typeparam name="U"></typeparam>
+#endif
+    [Tested]
+    public virtual void InsertAll<U>(int index, SCG.IEnumerable<U> items) where U : T
+    {
+      updatecheck();
+      if (index < 0 || index > size)
+        throw new IndexOutOfRangeException();
+      index += offset;
+      int toadd = EnumerableBase<U>.countItems(items);
+      if (toadd == 0)
+        return;
+      if (toadd + underlyingsize > array.Length)
+        expand(toadd + underlyingsize, underlyingsize);
+      if (underlyingsize > index)
+        Array.Copy(array, index, array, index + toadd, underlyingsize - index);
+      int i = index;
+      try
+      {
+
+        foreach (T item in items)
+        {
+#if HASHINDEX
+          KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, i);
+          if (itemIndex.FindOrAdd(ref p))
+            throw new DuplicateNotAllowedException("Item already in indexed list");
+#endif
+          array[i++] = item;
+        }
+      }
+      finally
+      {
+        int added = i - index;
+        if (added < toadd)
+        {
+          Array.Copy(array, index + toadd, array, i, underlyingsize - index);
+          Array.Clear(array, underlyingsize + added, toadd - added);
+        }
+        if (added > 0)
+        {
+          addtosize(added);
+#if HASHINDEX
+          reindex(i);
+#endif
+          fixViewsAfterInsert(added, index);
+          (underlying ?? this).raiseForInsertAll(index, added);
+        }
+      }
+    }
+    private void raiseForInsertAll(int index, int added)
+    {
+      if (ActiveEvents != 0)
+      {
+        if ((ActiveEvents & (EventTypeEnum.Added | EventTypeEnum.Inserted)) != 0)
+          for (int j = index; j < index + added; j++)
+          {
+            raiseItemInserted(array[j], j);
+            raiseItemsAdded(array[j], 1);
+          }
+        raiseCollectionChanged();
+      }
+    }
+
+#if HASHINDEX
+    /// <summary>
+    /// Insert an item at the front of this list;
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException">If the item is already in the list</exception>
+    /// <param name="item">The item to insert.</param>
+#else
+    /// <summary>
+    /// Insert an item at the front of this list;
+    /// </summary>
+    /// <param name="item">The item to insert.</param>
+#endif
+    [Tested]
+    public virtual void InsertFirst(T item)
+    {
+      updatecheck();
+      insert(0, item);
+      (underlying ?? this).raiseForInsert(offset, item);
+    }
+
+
+#if HASHINDEX
+    /// <summary>
+    /// Insert an item at the back of this list.
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException">If the item is already in the list</exception>
+    /// <param name="item">The item to insert.</param>
+#else
+    /// <summary>
+    /// Insert an item at the back of this list.
+    /// </summary>
+    /// <param name="item">The item to insert.</param>
+#endif
+    [Tested]
+    public virtual void InsertLast(T item)
+    {
+      updatecheck();
+      insert(size, item);
+      (underlying ?? this).raiseForInsert(size - 1 + offset, item);
+    }
+
+
+    //NOTE: if the filter throws an exception, no result will be returned.
+    /// <summary>
+    /// Create a new list consisting of the items of this list satisfying a 
+    /// certain predicate.
+    /// <para>The new list will be of type ArrayList</para>
+    /// </summary>
+    /// <param name="filter">The filter delegate defining the predicate.</param>
+    /// <returns>The new list.</returns>
+    [Tested]
+    public virtual IList<T> FindAll(Fun<T, bool> filter)
+    {
+      validitycheck();
+      int stamp = this.stamp;
+      ArrayList<T> res = new ArrayList<T>(itemequalityComparer);
+      int j = 0, rescap = res.array.Length;
+      for (int i = 0; i < size; i++)
+      {
+        T a = array[offset + i];
+        bool found = filter(a);
+        modifycheck(stamp);
+        if (found)
+        {
+          if (j == rescap) res.expand(rescap = 2 * rescap, j);
+          res.array[j++] = a;
+        }
+      }
+      res.size = j;
+#if HASHINDEX
+      res.reindex(0);
+#endif
+      return res;
+    }
+
+
+#if HASHINDEX
+    /// <summary>
+    /// Create a new list consisting of the results of mapping all items of this
+    /// list. The new list will use the default item equalityComparer for the item type V.
+    /// <para>The new list will be of type ArrayList</para>
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException">If <code>mapper</code>
+    /// creates duplicates</exception>
+    /// <typeparam name="V">The type of items of the new list</typeparam>
+    /// <param name="mapper">The delegate defining the map.</param>
+    /// <returns>The new list.</returns>
+#else
+    /// <summary>
+    /// Create a new list consisting of the results of mapping all items of this
+    /// list. The new list will use the default item equalityComparer for the item type V.
+    /// <para>The new list will be of type ArrayList</para>
+    /// </summary>
+    /// <typeparam name="V">The type of items of the new list</typeparam>
+    /// <param name="mapper">The delegate defining the map.</param>
+    /// <returns>The new list.</returns>
+#endif
+    [Tested]
+    public virtual IList<V> Map<V>(Fun<T, V> mapper)
+    {
+      validitycheck();
+
+      ArrayList<V> res = new ArrayList<V>(size);
+
+      return map<V>(mapper, res);
+    }
+
+#if HASHINDEX
+    /// <summary>
+    /// Create a new list consisting of the results of mapping all items of this
+    /// list. The new list will use a specified item equalityComparer for the item type.
+    /// <para>The new list will be of type ArrayList</para>
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException">If <code>mapper</code>
+    /// creates duplicates</exception>
+    /// <typeparam name="V">The type of items of the new list</typeparam>
+    /// <param name="mapper">The delegate defining the map.</param>
+    /// <param name="itemequalityComparer">The item equalityComparer to use for the new list</param>
+    /// <returns>The new list.</returns>
+#else
+    /// <summary>
+    /// Create a new list consisting of the results of mapping all items of this
+    /// list. The new list will use a specified item equalityComparer for the item type.
+    /// <para>The new list will be of type ArrayList</para>
+    /// </summary>
+    /// <typeparam name="V">The type of items of the new list</typeparam>
+    /// <param name="mapper">The delegate defining the map.</param>
+    /// <param name="itemequalityComparer">The item equalityComparer to use for the new list</param>
+    /// <returns>The new list.</returns>
+#endif
+    public virtual IList<V> Map<V>(Fun<T, V> mapper, SCG.IEqualityComparer<V> itemequalityComparer)
+    {
+      validitycheck();
+
+      ArrayList<V> res = new ArrayList<V>(size, itemequalityComparer);
+
+      return map<V>(mapper, res);
+    }
+
+    private IList<V> map<V>(Fun<T, V> mapper, ArrayList<V> res)
+    {
+      int stamp = this.stamp;
+      if (size > 0)
+        for (int i = 0; i < size; i++)
+        {
+          V mappeditem = mapper(array[offset + i]);
+          modifycheck(stamp);
+#if HASHINDEX
+          KeyValuePair<V, int> p = new KeyValuePair<V, int>(mappeditem, i);
+          if (res.itemIndex.FindOrAdd(ref p))
+            throw new ArgumentException("Mapped item already in indexed list");
+#endif
+          res.array[i] = mappeditem;
+        }
+      res.size = size;
+      return res;
+    }
+
+    /// <summary>
+    /// Remove one item from the list: from the front if <code>FIFO</code>
+    /// is true, else from the back.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public virtual T Remove()
+    {
+      updatecheck();
+      if (size == 0)
+        throw new NoSuchItemException("List is empty");
+
+      T item = removeAt(fIFO ? 0 : size - 1);
+      (underlying ?? this).raiseForRemove(item);
+      return item;
+    }
+
+    /// <summary>
+    /// Remove one item from the fromnt of the list.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public virtual T RemoveFirst()
+    {
+      updatecheck();
+      if (size == 0)
+        throw new NoSuchItemException("List is empty");
+
+      T item = removeAt(0);
+      (underlying ?? this).raiseForRemoveAt(offset, item);
+      return item;
+    }
+
+
+    /// <summary>
+    /// Remove one item from the back of the list.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public virtual T RemoveLast()
+    {
+      updatecheck();
+      if (size == 0)
+        throw new NoSuchItemException("List is empty");
+
+      T item = removeAt(size - 1);
+      (underlying ?? this).raiseForRemoveAt(size + offset, item);
+      return item;
+    }
+
+    /// <summary>
+    /// Create a list view on this list. 
+    /// </summary>
+    /// <exception cref="ArgumentOutOfRangeException"> if the start or count is negative
+    /// or the range does not fit within list.</exception>
+    /// <param name="start">The index in this list of the start of the view.</param>
+    /// <param name="count">The size of the view.</param>
+    /// <returns>The new list view.</returns>
+    [Tested]
+    public virtual IList<T> View(int start, int count)
+    {
+      validitycheck();
+      checkRange(start, count);
+      if (views == null)
+        views = new WeakViewList<ArrayList<T>>();
+      ArrayList<T> retval = (ArrayList<T>)MemberwiseClone();
+
+
+      retval.underlying = underlying != null ? underlying : this;
+      retval.offset = start + offset;
+      retval.size = count;
+      retval.myWeakReference = views.Add(retval);
+      return retval;
+    }
+
+    /// <summary>
+    /// Create a list view on this list containing the (first) occurrence of a particular item.
+    /// <para>Returns <code>null</code> if the item is not in this list.</para>
+    /// </summary>
+    /// <param name="item">The item to find.</param>
+    /// <returns>The new list view.</returns>
+    [Tested]
+    public virtual IList<T> ViewOf(T item)
+    {
+      int index = indexOf(item);
+      if (index < 0)
+        return null;
+      return View(index, 1);
+    }
+
+
+    /// <summary>
+    /// Create a list view on this list containing the last occurrence of a particular item. 
+    /// <para>Returns <code>null</code> if the item is not in this list.</para>
+    /// </summary>
+    /// <param name="item">The item to find.</param>
+    /// <returns>The new list view.</returns>
+    [Tested]
+    public virtual IList<T> LastViewOf(T item)
+    {
+      int index = lastIndexOf(item);
+      if (index < 0)
+        return null;
+      return View(index, 1);
+    }
+
+    /// <summary>
+    /// Null if this list is not a view.
+    /// </summary>
+    /// <value>Underlying list for view.</value>
+    [Tested]
+    public virtual IList<T> Underlying { [Tested]get { return underlying; } }
+
+
+    /// <summary>
+    /// </summary>
+    /// <value>Offset for this list view or 0 for an underlying list.</value>
+    [Tested]
+    public virtual int Offset { [Tested]get { return offset; } }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public virtual bool IsValid { get { return isValid; } }
+
+    /// <summary>
+    /// Slide this list view along the underlying list.
+    /// </summary>
+    /// <exception cref="NotAViewException"> if this list is not a view.</exception>
+    /// <exception cref="ArgumentOutOfRangeException"> if the operation
+    /// would bring either end of the view outside the underlying list.</exception>
+    /// <param name="offset">The signed amount to slide: positive to slide
+    /// towards the end.</param>
+    [Tested]
+    public virtual IList<T> Slide(int offset)
+    {
+      if (!TrySlide(offset, size))
+        throw new ArgumentOutOfRangeException();
+      return this;
+    }
+
+
+    /// <summary>
+    /// Slide this list view along the underlying list, changing its size.
+    /// </summary>
+    /// <exception cref="NotAViewException"> if this list is not a view.</exception>
+    /// <exception cref="ArgumentOutOfRangeException"> if the operation
+    /// would bring either end of the view outside the underlying list.</exception>
+    /// <param name="offset">The signed amount to slide: positive to slide
+    /// towards the end.</param>
+    /// <param name="size">The new size of the view.</param>
+    [Tested]
+    public virtual IList<T> Slide(int offset, int size)
+    {
+      if (!TrySlide(offset, size))
+        throw new ArgumentOutOfRangeException();
+      return this;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <exception cref="NotAViewException"> if this list is not a view.</exception>
+    /// <param name="offset"></param>
+    /// <returns></returns>
+    [Tested]
+    public virtual bool TrySlide(int offset)
+    {
+      return TrySlide(offset, size);
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <exception cref="NotAViewException"> if this list is not a view.</exception>
+    /// <param name="offset"></param>
+    /// <param name="size"></param>
+    /// <returns></returns>
+    [Tested]
+    public virtual bool TrySlide(int offset, int size)
+    {
+      updatecheck();
+      if (underlying == null)
+        throw new NotAViewException("Not a view");
+
+      int newoffset = this.offset + offset;
+      int newsize = size;
+
+      if (newoffset < 0 || newsize < 0 || newoffset + newsize > underlyingsize)
+        return false;
+
+      this.offset = newoffset;
+      this.size = newsize;
+      return true;
+    }
+
+    /// <summary>
+    /// 
+    /// <para>Returns null if <code>otherView</code> is strictly to the left of this view</para>
+    /// </summary>
+    /// <param name="otherView"></param>
+    /// <exception cref="IncompatibleViewException">If otherView does not have the same underlying list as this</exception>
+    /// <returns></returns>
+    public virtual IList<T> Span(IList<T> otherView)
+    {
+      if ((otherView == null) || ((otherView.Underlying ?? otherView) != (underlying ?? this)))
+        throw new IncompatibleViewException();
+      if (otherView.Offset + otherView.Count - Offset < 0)
+        return null;
+      return (underlying ?? this).View(Offset, otherView.Offset + otherView.Count - Offset);
+    }
+
+    /// <summary>
+    /// Reverst the list so the items are in the opposite sequence order.
+    /// </summary>
+    [Tested]
+    public virtual void Reverse()
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      for (int i = 0, length = size / 2, end = offset + size - 1; i < length; i++)
+      {
+        T swap = array[offset + i];
+
+        array[offset + i] = array[end - i];
+        array[end - i] = swap;
+      }
+#if HASHINDEX
+      reindex(offset, offset + size);
+#endif
+      //TODO: be more forgiving wrt. disposing
+      disposeOverlappingViews(true);
+      (underlying ?? this).raiseCollectionChanged();
+    }
+
+    /// <summary>
+    /// Check if this list is sorted according to the default sorting order
+    /// for the item type T, as defined by the <see cref="T:C5.Comparer`1"/> class 
+    /// </summary>
+    /// <exception cref="NotComparableException">if T is not comparable</exception>
+    /// <returns>True if the list is sorted, else false.</returns>
+    [Tested]
+    public bool IsSorted() { return IsSorted(Comparer<T>.Default); }
+
+    /// <summary>
+    /// Check if this list is sorted according to a specific sorting order.
+    /// </summary>
+    /// <param name="c">The comparer defining the sorting order.</param>
+    /// <returns>True if the list is sorted, else false.</returns>
+    [Tested]
+    public virtual bool IsSorted(SCG.IComparer<T> c)
+    {
+      validitycheck();
+      for (int i = offset + 1, end = offset + size; i < end; i++)
+        if (c.Compare(array[i - 1], array[i]) > 0)
+          return false;
+
+      return true;
+    }
+
+    /// <summary>
+    /// Sort the items of the list according to the default sorting order
+    /// for the item type T, as defined by the Comparer[T] class 
+    /// (<see cref="T:C5.Comparer`1"/>).
+    /// </summary>
+    /// <exception cref="InvalidOperationException">if T is not comparable</exception>
+    public virtual void Sort()
+    {
+      Sort(Comparer<T>.Default);
+    }
+
+
+    /// <summary>
+    /// Sort the items of the list according to a specific sorting order.
+    /// </summary>
+    /// <param name="comparer">The comparer defining the sorting order.</param>
+    [Tested]
+    public virtual void Sort(SCG.IComparer<T> comparer)
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      Sorting.IntroSort<T>(array, offset, size, comparer);
+      disposeOverlappingViews(false);
+#if HASHINDEX
+      reindex(offset, offset + size);
+#endif
+      (underlying ?? this).raiseCollectionChanged();
+    }
+
+
+    /// <summary>
+    /// Randomly shuffle the items of this list. 
+    /// </summary>
+    public virtual void Shuffle() { Shuffle(new C5Random()); }
+
+
+    /// <summary>
+    /// Shuffle the items of this list according to a specific random source.
+    /// </summary>
+    /// <param name="rnd">The random source.</param>
+    public virtual void Shuffle(Random rnd)
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      for (int i = offset, top = offset + size, end = top - 1; i < end; i++)
+      {
+        int j = rnd.Next(i, top);
+        if (j != i)
+        {
+          T tmp = array[i];
+          array[i] = array[j];
+          array[j] = tmp;
+        }
+      }
+      disposeOverlappingViews(false);
+#if HASHINDEX
+      reindex(offset, offset + size);
+#endif
+      (underlying ?? this).raiseCollectionChanged();
+    }
+    #endregion
+
+    #region IIndexed<T> Members
+
+    /// <summary>
+    /// Search for an item in the list going forwrds from the start.
+    /// </summary>
+    /// <param name="item">Item to search for.</param>
+    /// <returns>Index of item from start.</returns>
+    [Tested]
+    public virtual int IndexOf(T item) { validitycheck(); return indexOf(item); }
+
+
+    /// <summary>
+    /// Search for an item in the list going backwords from the end.
+    /// </summary>
+    /// <param name="item">Item to search for.</param>
+    /// <returns>Index of item from the end.</returns>
+    [Tested]
+    public virtual int LastIndexOf(T item) { validitycheck(); return lastIndexOf(item); }
+
+
+    /// <summary>
+    /// Remove the item at a specific position of the list.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt;= the size of the collection.</exception>
+    /// <param name="index">The index of the item to remove.</param>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public virtual T RemoveAt(int index)
+    {
+      updatecheck();
+      if (index < 0 || index >= size)
+        throw new IndexOutOfRangeException("Index out of range for sequenced collection");
+
+      T item = removeAt(index);
+      (underlying ?? this).raiseForRemoveAt(offset + index, item);
+      return item;
+    }
+
+
+    /// <summary>
+    /// Remove all items in an index interval.
+    /// </summary>
+    /// <exception cref="ArgumentOutOfRangeException">If <code>start</code>
+    /// and <code>count</code> does not describe a valid interval in the list</exception> 
+    /// <param name="start">The index of the first item to remove.</param>
+    /// <param name="count">The number of items to remove.</param>
+    [Tested]
+    public virtual void RemoveInterval(int start, int count)
+    {
+      updatecheck();
+      if (count == 0)
+        return;
+      checkRange(start, count);
+      start += offset;
+      fixViewsBeforeRemove(start, count);
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+      for (int i = start, end = start + count; i < end; i++)
+      {
+        p.Key = array[i];
+        itemIndex.Remove(p);
+      }
+#endif
+      Array.Copy(array, start + count, array, start, underlyingsize - start - count);
+      addtosize(-count);
+      Array.Clear(array, underlyingsize, count);
+#if HASHINDEX
+      reindex(start);
+#endif
+      (underlying ?? this).raiseForRemoveInterval(start, count);
+    }
+    void raiseForRemoveInterval(int start, int count)
+    {
+      if (ActiveEvents != 0)
+      {
+        raiseCollectionCleared(size == 0, count, start);
+        raiseCollectionChanged();
+      }
+    }
+    #endregion
+
+    #region ICollection<T> Members
+
+    /// <summary>
+    /// The value is symbolic indicating the type of asymptotic complexity
+    /// in terms of the size of this collection (worst-case or amortized as
+    /// relevant).
+    /// </summary>
+    /// <value>Speed.Linear</value>
+    [Tested]
+    public virtual Speed ContainsSpeed
+    {
+      [Tested]
+      get
+      {
+#if HASHINDEX
+        return Speed.Constant;
+#else
+        return Speed.Linear;
+#endif
+      }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    [Tested]
+    public override int GetUnsequencedHashCode()
+    { validitycheck(); return base.GetUnsequencedHashCode(); }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="that"></param>
+    /// <returns></returns>
+    [Tested]
+    public override bool UnsequencedEquals(ICollection<T> that)
+    { validitycheck(); return base.UnsequencedEquals(that); }
+
+    /// <summary>
+    /// Check if this collection contains (an item equivalent to according to the
+    /// itemequalityComparer) a particular value.
+    /// </summary>
+    /// <param name="item">The value to check for.</param>
+    /// <returns>True if the items is in this collection.</returns>
+    [Tested]
+    public virtual bool Contains(T item)
+    { validitycheck(); return indexOf(item) >= 0; }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, return in the ref argument (a
+    /// binary copy of) the actual value found.
+    /// </summary>
+    /// <param name="item">The value to look for.</param>
+    /// <returns>True if the items is in this collection.</returns>
+    [Tested]
+    public virtual bool Find(ref T item)
+    {
+      validitycheck();
+
+      int i;
+
+      if ((i = indexOf(item)) >= 0)
+      {
+        item = array[offset + i];
+        return true;
+      }
+
+      return false;
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, update the item in the collection 
+    /// to with a binary copy of the supplied value. This will only update the first 
+    /// mathching item.
+    /// </summary>
+    /// <param name="item">Value to update.</param>
+    /// <returns>True if the item was found and hence updated.</returns>
+    [Tested]
+    public virtual bool Update(T item)
+    {
+      T olditem;
+      return Update(item, out olditem);
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item"></param>
+    /// <param name="olditem"></param>
+    /// <returns></returns>
+    public virtual bool Update(T item, out T olditem)
+    {
+      updatecheck();
+      int i;
+
+      if ((i = indexOf(item)) >= 0)
+      {
+        olditem = array[offset + i];
+        array[offset + i] = item;
+#if HASHINDEX
+        itemIndex.Update(new KeyValuePair<T, int>(item, offset + i));
+#endif
+        (underlying ?? this).raiseForUpdate(item, olditem);
+        return true;
+      }
+
+      olditem = default(T);
+      return false;
+    }
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, return in the ref argument (a
+    /// binary copy of) the actual value found. Else, add the item to the collection.
+    /// </summary>
+    /// <param name="item">The value to look for.</param>
+    /// <returns>True if the item was found (hence not added).</returns>
+    [Tested]
+    public virtual bool FindOrAdd(ref T item)
+    {
+      updatecheck();
+      if (Find(ref item))
+        return true;
+
+      Add(item);
+      return false;
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, update the item in the collection 
+    /// to with a binary copy of the supplied value. This will only update the first 
+    /// mathching item.
+    /// </summary>
+    /// <param name="item">Value to update.</param>
+    /// <returns>True if the item was found and hence updated.</returns>
+    [Tested]
+    public virtual bool UpdateOrAdd(T item)
+    {
+      updatecheck();
+      if (Update(item))
+        return true;
+
+      Add(item);
+      return false;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item"></param>
+    /// <param name="olditem"></param>
+    /// <returns></returns>
+    public virtual bool UpdateOrAdd(T item, out T olditem)
+    {
+      updatecheck();
+      if (Update(item, out olditem))
+        return true;
+
+      Add(item);
+      olditem = default(T);
+      return false;
+    }
+
+    /// <summary>
+    /// Remove a particular item from this list. The item will be searched 
+    /// for from the end of the list if <code>FIFO == false</code> (the default), 
+    /// else from the start.
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    /// <returns>True if the item was found (and removed).</returns>
+    [Tested]
+    public virtual bool Remove(T item)
+    {
+      updatecheck();
+
+      int i = fIFO ? indexOf(item) : lastIndexOf(item);
+
+      if (i < 0)
+        return false;
+
+      T removeditem = removeAt(i);
+      (underlying ?? this).raiseForRemove(removeditem);
+      return true;
+    }
+
+
+    /// <summary>
+    /// Remove the first copy of a particular item from this collection if found.
+    /// If an item was removed, report a binary copy of the actual item removed in 
+    /// the argument. The item will be searched 
+    /// for from the end of the list if <code>FIFO == false</code> (the default), 
+    /// else from the start.
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    /// <param name="removeditem">The removed value.</param>
+    /// <returns>True if the item was found (and removed).</returns>
+    [Tested]
+    public virtual bool Remove(T item, out T removeditem)
+    {
+      updatecheck();
+
+      int i = fIFO ? indexOf(item) : lastIndexOf(item);
+
+      if (i < 0)
+      {
+        removeditem = default(T);
+        return false;
+      }
+
+      removeditem = removeAt(i);
+      (underlying ?? this).raiseForRemove(removeditem);
+      return true;
+    }
+
+
+    //TODO: remove from end or according to FIFO?
+    /// <summary>
+    /// Remove all items in another collection from this one, taking multiplicities into account.
+    /// Matching items will be removed from the front. Current implementation is not optimal.
+    /// </summary>
+    /// <typeparam name="U"></typeparam>
+    /// <param name="items">The items to remove.</param>
+    [Tested]
+    public virtual void RemoveAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      //TODO: reactivate the old code for small sizes
+      HashBag<T> toremove = new HashBag<T>(itemequalityComparer);
+      toremove.AddAll(items);
+      if (toremove.Count == 0)
+        return;
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+#endif
+      while (i < end)
+      {
+        T item;
+        //pass by a stretch of nodes
+        while (i < end && !toremove.Contains(item = array[i]))
+        {
+#if HASHINDEX
+          if (j < i)
+          {
+            p.Key = item;
+            p.Value = j;
+            itemIndex.Update(p);
+          }
+#endif
+          //if (j<i)
+          array[j] = item;
+          i++; j++;
+        }
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && toremove.Remove(item = array[i]))
+        {
+#if HASHINDEX
+          p.Key = item;
+          itemIndex.Remove(p);
+#endif
+          if (mustFire)
+            raiseHandler.Remove(item);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+#if HASHINDEX
+      reindex(j);
+#endif
+      if (mustFire)
+        raiseHandler.Raise();
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="predicate"></param>
+    void RemoveAll(Fun<T, bool> predicate)
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+#endif
+      while (i < end)
+      {
+        T item;
+        //pass by a stretch of nodes
+        while (i < end && !predicate(item = array[i]))
+        {
+          updatecheck();
+#if HASHINDEX
+          if (j < i)
+          {
+            p.Key = item;
+            p.Value = j;
+            itemIndex.Update(p);
+          }
+#endif
+          //if (j<i)
+          array[j] = item;
+          i++; j++;
+        }
+        updatecheck();
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && predicate(item = array[i]))
+        {
+          updatecheck();
+#if HASHINDEX
+          p.Key = item;
+          itemIndex.Remove(p);
+#endif
+          if (mustFire)
+            raiseHandler.Remove(item);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+        updatecheck();
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+#if HASHINDEX
+      reindex(j);
+#endif
+      if (mustFire)
+        raiseHandler.Raise();
+    }
+
+    /// <summary>
+    /// Remove all items from this collection, resetting internal array size.
+    /// </summary>
+    [Tested]
+    public override void Clear()
+    {
+      if (underlying == null)
+      {
+        updatecheck();
+        if (size == 0)
+          return;
+        int oldsize = size;
+        fixViewsBeforeRemove(0, size);
+#if HASHINDEX
+        itemIndex.Clear();
+#endif
+        array = new T[8];
+        size = 0;
+        (underlying ?? this).raiseForRemoveInterval(offset, oldsize);
+      }
+      else
+        RemoveInterval(0, size);
+    }
+
+    /// <summary>
+    /// Remove all items not in some other collection from this one, taking multiplicities into account.
+    /// Items are retained front first.  
+    /// </summary>
+    /// <typeparam name="U"></typeparam>
+    /// <param name="items">The items to retain.</param>
+    [Tested]
+    public virtual void RetainAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      HashBag<T> toretain = new HashBag<T>(itemequalityComparer);
+      toretain.AddAll(items);
+      if (toretain.Count == 0)
+      {
+        Clear();
+        return;
+      }
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+#endif
+      while (i < end)
+      {
+        T item;
+        //pass by a stretch of nodes
+        while (i < end && toretain.Remove(item = array[i]))
+        {
+#if HASHINDEX
+          if (j < i)
+          {
+            p.Key = item;
+            p.Value = j;
+            itemIndex.Update(p);
+          }
+#endif
+          //if (j<i)
+          array[j] = item;
+          i++; j++;
+        }
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && !toretain.Contains(item = array[i]))
+        {
+#if HASHINDEX
+          p.Key = item;
+          itemIndex.Remove(p);
+#endif
+          if (mustFire)
+            raiseHandler.Remove(item);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+#if HASHINDEX
+      reindex(j);
+#endif
+      raiseHandler.Raise();
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="predicate"></param>
+    void RetainAll(Fun<T, bool> predicate)
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+#endif
+      while (i < end)
+      {
+        T item;
+        //pass by a stretch of nodes
+        while (i < end && predicate(item = array[i]))
+        {
+          updatecheck();
+#if HASHINDEX
+          if (j < i)
+          {
+            p.Key = item;
+            p.Value = j;
+            itemIndex.Update(p);
+          }
+#endif
+          //if (j<i)
+          array[j] = item;
+          i++; j++;
+        }
+        updatecheck();
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && !predicate(item = array[i]))
+        {
+          updatecheck();
+#if HASHINDEX
+          p.Key = item;
+          itemIndex.Remove(p);
+#endif
+          if (mustFire)
+            raiseHandler.Remove(item);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+        updatecheck();
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+#if HASHINDEX
+      reindex(j);
+#endif
+      raiseHandler.Raise();
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains all the values in another collection,
+    /// taking multiplicities into account.
+    /// Current implementation is not optimal.
+    /// </summary>
+    /// <param name="items">The </param>
+    /// <typeparam name="U"></typeparam>
+    /// <returns>True if all values in <code>items</code>is in this collection.</returns>
+    [Tested]
+    public virtual bool ContainsAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      validitycheck();
+#if HASHINDEX
+      foreach (T item in items)
+        if (indexOf(item) < 0)
+          return false;
+
+      return true;
+#else
+      //TODO: use aux hash bag to obtain linear time procedure
+      HashBag<T> tomatch = new HashBag<T>(itemequalityComparer);
+      tomatch.AddAll(items);
+      if (tomatch.Count == 0)
+        return true;
+      for (int i = offset, end = offset + size; i < end; i++)
+      {
+        tomatch.Remove(array[i]);
+        if (tomatch.Count == 0)
+          return true;
+      }
+      return false;
+#endif
+    }
+
+
+    /// <summary>
+    /// Count the number of items of the collection equal to a particular value.
+    /// Returns 0 if and only if the value is not in the collection.
+    /// </summary>
+    /// <param name="item">The value to count.</param>
+    /// <returns>The number of copies found.</returns>
+    [Tested]
+    public virtual int ContainsCount(T item)
+    {
+      validitycheck();
+#if HASHINDEX
+      return indexOf(item) >= 0 ? 1 : 0;
+#else
+      int count = 0;
+      for (int i = 0; i < size; i++)
+        if (equals(item, array[offset + i]))
+          count++;
+      return count;
+#endif
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public virtual ICollectionValue<T> UniqueItems()
+    {
+#if HASHINDEX
+      return this;
+#else
+      HashBag<T> hashbag = new HashBag<T>(itemequalityComparer);
+      hashbag.AddAll(this);
+      return hashbag.UniqueItems();
+#endif
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public virtual ICollectionValue<KeyValuePair<T, int>> ItemMultiplicities()
+    {
+#if HASHINDEX
+      return new MultiplicityOne<T>(this);
+#else
+      HashBag<T> hashbag = new HashBag<T>(itemequalityComparer);
+      hashbag.AddAll(this);
+      return hashbag.ItemMultiplicities();
+#endif
+    }
+
+
+
+
+
+    /// <summary>
+    /// Remove all items equal to a given one.
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    [Tested]
+    public virtual void RemoveAllCopies(T item)
+    {
+#if HASHINDEX
+      Remove(item);
+#else
+      updatecheck();
+      if (size == 0)
+        return;
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+      while (i < end)
+      {
+        //pass by a stretch of nodes
+        while (i < end && !equals(item, array[i]))
+          array[j++] = array[i++];
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && equals(item, array[i]))
+        {
+          if (mustFire)
+            raiseHandler.Remove(array[i]);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+      raiseHandler.Raise();
+#endif
+    }
+
+
+    //TODO: check views
+    /// <summary>
+    /// Check the integrity of the internal data structures of this array list.
+    /// </summary>
+    /// <returns>True if check does not fail.</returns>
+    [Tested]
+    public override bool Check()
+    {
+      bool retval = true;
+
+      if (underlyingsize > array.Length)
+      {
+        Console.WriteLine("underlyingsize ({0}) > array.Length ({1})", size, array.Length);
+        return false;
+      }
+
+      if (offset + size > underlyingsize)
+      {
+        Console.WriteLine("offset({0})+size({1}) > underlyingsize ({2})", offset, size, underlyingsize);
+        return false;
+      }
+
+      if (offset < 0)
+      {
+        Console.WriteLine("offset({0}) < 0", offset);
+        return false;
+      }
+
+      for (int i = 0; i < underlyingsize; i++)
+      {
+        if ((object)(array[i]) == null)
+        {
+          Console.WriteLine("Bad element: null at (base)index {0}", i);
+          retval = false;
+        }
+      }
+
+      for (int i = underlyingsize, length = array.Length; i < length; i++)
+      {
+        if (!equals(array[i], default(T)))
+        {
+          Console.WriteLine("Bad element: != default(T) at (base)index {0}", i);
+          retval = false;
+        }
+      }
+
+      {
+        ArrayList<T> u = underlying ?? this;
+        if (u.views != null)
+          foreach (ArrayList<T> v in u.views)
+          {
+            if (u.array != v.array)
+            {
+              Console.WriteLine("View from {0} of length has different base array than the underlying list", v.offset, v.size);
+              retval = false;
+            }
+          }
+      }
+
+
+#if HASHINDEX
+      if (underlyingsize != itemIndex.Count)
+      {
+        Console.WriteLine("size ({0})!= index.Count ({1})", size, itemIndex.Count);
+        retval = false;
+      }
+
+      for (int i = 0; i < underlyingsize; i++)
+      {
+        KeyValuePair<T, int> p = new KeyValuePair<T, int>(array[i]);
+
+        if (!itemIndex.Find(ref p))
+        {
+          Console.WriteLine("Item {1} at {0} not in hashindex", i, array[i]);
+          retval = false;
+        }
+
+        if (p.Value != i)
+        {
+          Console.WriteLine("Item {1} at {0} has hashindex {2}", i, array[i], p.Value);
+          retval = false;
+        }
+      }
+#endif
+      return retval;
+    }
+
+    #endregion
+
+    #region IExtensible<T> Members
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value>True, indicating array list has bag semantics.</value>
+    [Tested]
+    public virtual bool AllowsDuplicates
+    {
+      [Tested]
+      get
+      {
+#if HASHINDEX
+        return false;
+#else
+        return true;
+#endif
+      }
+    }
+
+    /// <summary>
+    /// By convention this is true for any collection with set semantics.
+    /// </summary>
+    /// <value>True if only one representative of a group of equal items 
+    /// is kept in the collection together with the total count.</value>
+    public virtual bool DuplicatesByCounting
+    {
+      get
+      {
+#if HASHINDEX
+        return true;
+#else
+        return false;
+#endif
+      }
+    }
+
+    /// <summary>
+    /// Add an item to end of this list.
+    /// </summary>
+    /// <param name="item">The item to add.</param>
+    /// <returns>True</returns>
+    [Tested]
+    public virtual bool Add(T item)
+    {
+      updatecheck();
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, size + offset);
+      if (itemIndex.FindOrAdd(ref p))
+        return false;
+#endif
+      baseinsert(size, item);
+#if HASHINDEX
+      reindex(size + offset);
+#endif
+      (underlying ?? this).raiseForAdd(item);
+      return true;
+    }
+
+
+    /// <summary>
+    /// Add the elements from another collection to this collection.
+    /// </summary>
+    /// <typeparam name="U"></typeparam>
+    /// <param name="items"></param>
+    [Tested]
+    public virtual void AddAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      updatecheck();
+      int toadd = EnumerableBase<U>.countItems(items);
+      if (toadd == 0)
+        return;
+
+      if (toadd + underlyingsize > array.Length)
+        expand(toadd + underlyingsize, underlyingsize);
+
+      int i = size + offset;
+      if (underlyingsize > i)
+        Array.Copy(array, i, array, i + toadd, underlyingsize - i);
+      try
+      {
+        foreach (T item in items)
+        {
+#if HASHINDEX
+          KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, i);
+          if (itemIndex.FindOrAdd(ref p))
+            continue;
+#endif
+          array[i++] = item;
+        }
+      }
+      finally
+      {
+        int added = i - size - offset;
+        if (added < toadd)
+        {
+          Array.Copy(array, size + offset + toadd, array, i, underlyingsize - size - offset);
+          Array.Clear(array, underlyingsize + added, toadd - added);
+        }
+        if (added > 0)
+        {
+          addtosize(added);
+#if HASHINDEX
+          reindex(i);
+#endif
+          fixViewsAfterInsert(added, i - added);
+          (underlying ?? this).raiseForAddAll(i - added, added);
+        }
+      }
+    }
+    private void raiseForAddAll(int start, int added)
+    {
+      if ((ActiveEvents & EventTypeEnum.Added) != 0)
+        for (int i = start, end = start + added; i < end; i++)
+          raiseItemsAdded(array[i], 1);
+      raiseCollectionChanged();
+    }
+
+    #endregion
+
+    #region IDirectedEnumerable<T> Members
+
+    /// <summary>
+    /// Create a collection containing the same items as this collection, but
+    /// whose enumerator will enumerate the items backwards. The new collection
+    /// will become invalid if the original is modified. Method typicaly used as in
+    /// <code>foreach (T x in coll.Backwards()) {...}</code>
+    /// </summary>
+    /// <returns>The backwards collection.</returns>
+    [Tested]
+    IDirectedEnumerable<T> IDirectedEnumerable<T>.Backwards() { return Backwards(); }
+
+    #endregion
+
+    #region ICollectionValue<T> Members
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value>The number of items in this collection</value>
+    [Tested]
+    public override int Count { [Tested]get { validitycheck(); return size; } }
+    #endregion
+
+    #region IEnumerable<T> Members
+    //TODO: make tests of all calls on a disposed view throws the right exception! (Which should be C5.InvalidListViewException)
+    /// <summary>
+    /// Create an enumerator for the collection
+    /// </summary>
+    /// <returns>The enumerator</returns>
+    [Tested]
+    public override SCG.IEnumerator<T> GetEnumerator()
+    {
+      validitycheck();
+      return base.GetEnumerator();
+    }
+    #endregion
+
+#if HASHINDEX
+#else
+    #region IStack<T> Members
+
+    /// <summary>
+    /// Push an item to the top of the stack.
+    /// </summary>
+    /// <param name="item">The item</param>
+    [Tested]
+    public virtual void Push(T item)
+    {
+      InsertLast(item);
+    }
+
+    /// <summary>
+    /// Pop the item at the top of the stack from the stack.
+    /// </summary>
+    /// <returns>The popped item.</returns>
+    [Tested]
+    public virtual T Pop()
+    {
+      return RemoveLast();
+    }
+
+    #endregion
+
+    #region IQueue<T> Members
+
+    /// <summary>
+    /// Enqueue an item at the back of the queue. 
+    /// </summary>
+    /// <param name="item">The item</param>
+    [Tested]
+    public virtual void Enqueue(T item)
+    {
+      InsertLast(item);
+    }
+
+    /// <summary>
+    /// Dequeue an item from the front of the queue.
+    /// </summary>
+    /// <returns>The item</returns>
+    [Tested]
+    public virtual T Dequeue()
+    {
+      return RemoveFirst();
+    }
+
+    #endregion
+#endif
+    #region IDisposable Members
+
+    /// <summary>
+    /// Invalidate this list. If a view, just invalidate the view. 
+    /// If not a view, invalidate the list and all views on it.
+    /// </summary>
+    public virtual void Dispose()
+    {
+      Dispose(false);
+    }
+
+    void Dispose(bool disposingUnderlying)
+    {
+      if (isValid)
+      {
+        if (underlying != null)
+        {
+          isValid = false;
+          if (!disposingUnderlying && views != null)
+            views.Remove(myWeakReference);
+          underlying = null;
+          views = null;
+          myWeakReference = null;
+        }
+        else
+        {
+          //isValid = false;
+          if (views != null)
+            foreach (ArrayList<T> view in views)
+              view.Dispose(true);
+          Clear();
+        }
+      }
+    }
+
+    #endregion
+
+    #region ICloneable Members
+
+    /// <summary>
+    /// Make a shallow copy of this ArrayList.
+    /// </summary>
+    /// <returns></returns>
+    public virtual object Clone()
+    {
+      ArrayList<T> clone = new ArrayList<T>(size, itemequalityComparer);
+      clone.AddAll(this);
+      return clone;
+    }
+
+    #endregion
+
+    #region ISerializable Members
+    /*
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="info"></param>
+    /// <param name="context"></param>
+    public ArrayList(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) :
+      this(info.GetInt32("sz"),(SCG.IEqualityComparer<T>)(info.GetValue("eq",typeof(SCG.IEqualityComparer<T>))))
+    {
+      size = info.GetInt32("sz");
+      for (int i = 0; i < size; i++)
+      {
+        array[i] = (T)(info.GetValue("elem" + i,typeof(T)));
+      }
+#if HASHINDEX
+      reindex(0);
+#endif      
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="info"></param>
+    /// <param name="context"></param>
+    public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
+    {
+      info.AddValue("sz", size);
+      info.AddValue("eq", EqualityComparer);
+      for (int i = 0; i < size; i++)
+			{
+        info.AddValue("elem" + i, array[i + offset]);
+      }
+    }
+*/
+    #endregion
+
+    #region System.Collections.Generic.IList<T> Members
+
+    void System.Collections.Generic.IList<T>.RemoveAt(int index)
+    {
+      RemoveAt(index);
+    }
+
+    void System.Collections.Generic.ICollection<T>.Add(T item)
+    {
+      Add(item);
+    }
+
+    #endregion
+
+    #region System.Collections.ICollection Members
+
+    bool System.Collections.ICollection.IsSynchronized
+    {
+      get { return false; }
+    }
+
+    [Obsolete]
+    Object System.Collections.ICollection.SyncRoot
+    {
+      get { return underlying != null ? ((System.Collections.ICollection)underlying).SyncRoot : array; }
+    }
+
+    void System.Collections.ICollection.CopyTo(Array arr, int index)
+    {
+      if (index < 0 || index + Count > arr.Length)
+        throw new ArgumentOutOfRangeException();
+
+      foreach (T item in this)
+        arr.SetValue(item, index++);
+    }
+
+    #endregion
+
+    #region System.Collections.IList Members
+
+    Object System.Collections.IList.this[int index]
+    {
+      get { return this[index]; }
+      set { this[index] = (T)value; }
+    }
+
+    int System.Collections.IList.Add(Object o)
+    {
+      bool added = Add((T)o);
+      // What position to report if item not added? SC.IList.Add doesn't say
+      return added ? Count - 1 : -1;
+    }
+
+    bool System.Collections.IList.Contains(Object o)
+    {
+      return Contains((T)o);
+    }
+
+    int System.Collections.IList.IndexOf(Object o)
+    {
+      return Math.Max(-1, IndexOf((T)o));
+    }
+
+    void System.Collections.IList.Insert(int index, Object o)
+    {
+      Insert(index, (T)o);
+    }
+
+    void System.Collections.IList.Remove(Object o)
+    {
+      Remove((T)o);
+    }
+
+    void System.Collections.IList.RemoveAt(int index)
+    {
+      RemoveAt(index);
+    }
+
+    #endregion
+  }
+}
diff --git a/mcs/class/Mono.C5/C5/arrays/CircularQueue.cs b/mcs/class/Mono.C5/C5/arrays/CircularQueue.cs
index 4f06c0c7143..18b13bffe90 100644
--- a/mcs/class/Mono.C5/C5/arrays/CircularQueue.cs
+++ b/mcs/class/Mono.C5/C5/arrays/CircularQueue.cs
@@ -1,335 +1,335 @@
-/*

- Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft

- Permission is hereby granted, free of charge, to any person obtaining a copy

- of this software and associated documentation files (the "Software"), to deal

- in the Software without restriction, including without limitation the rights

- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

- copies of the Software, and to permit persons to whom the Software is

- furnished to do so, subject to the following conditions:

- 

- The above copyright notice and this permission notice shall be included in

- all copies or substantial portions of the Software.

- 

- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

- SOFTWARE.

-*/

-

-using System;

-using System.Diagnostics;

-using SCG = System.Collections.Generic;

-namespace C5

-{

-  /// <summary>

-  /// 

-  /// </summary>

-  /// <typeparam name="T"></typeparam>

-  public class CircularQueue<T> : SequencedBase<T>, IQueue<T>, IStack<T>

-  {

-    #region Fields

-    /*

-        Invariant: the itemes in the queue ar the elements from front upwards, 

-        possibly wrapping around at the end of array, to back.

-

-        if front<=back then size = back - front + 1;

-        else size = array.Length + back - front + 1;

-

-        */

-    int front, back;

-    /// <summary>

-    /// The internal container array is doubled when necessary, but never shrinked.

-    /// </summary>

-    T[] array;

-    bool forwards = true, original = true;

-    #endregion

-

-    #region Events

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public override EventTypeEnum ListenableEvents { get { return EventTypeEnum.Basic; } }

-

-    #endregion

-

-    #region Util

-    void expand()

-    {

-      int newlength = 2 * array.Length;

-      T[] newarray = new T[newlength];

-

-      if (front <= back)

-        Array.Copy(array, front, newarray, 0, size);

-      else

-      {

-        int half = array.Length - front;

-        Array.Copy(array, front, newarray, 0, half);

-        Array.Copy(array, 0, newarray, half, size - half);

-      }

-

-      front = 0;

-      back = size;

-      array = newarray;

-    }

-

-    #endregion

-

-    #region Constructors

-

-    /// <summary>

-    /// 

-    /// </summary>

-    public CircularQueue() : this(8) { }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="capacity"></param>

-    public CircularQueue(int capacity)

-      : base(EqualityComparer<T>.Default)

-    {

-      int newlength = 8;

-      while (newlength < capacity) newlength *= 2;

-      array = new T[newlength];

-    }

-

-    #endregion

-

-    #region IQueue<T> Members

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public virtual bool AllowsDuplicates { get { return true; } }

-

-    /// <summary>

-    /// Get the i'th item in the queue. The front of the queue is at index 0.

-    /// </summary>

-    /// <param name="i"></param>

-    /// <returns></returns>

-    public virtual T this[int i]

-    {

-      get

-      {

-        if (i < 0 || i >= size)

-          throw new IndexOutOfRangeException();

-        i = i + front;

-        //Bug fix by Steve Wallace 2006/02/10

-        return array[i >= array.Length ? i - array.Length : i];

-      }

-    }

-

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item"></param>

-    [Tested]

-    public virtual void Enqueue(T item)

-    {

-      if (!original)

-        throw new ReadOnlyCollectionException();

-      stamp++;

-      if (size == array.Length - 1) expand();

-      size++;

-      int oldback = back++;

-      if (back == array.Length) back = 0;

-      array[oldback] = item;

-      if (ActiveEvents != 0)

-        raiseForAdd(item);

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    [Tested]

-    public virtual T Dequeue()

-    {

-      if (!original)

-        throw new ReadOnlyCollectionException("Object is a non-updatable clone");

-      stamp++;

-      if (size == 0)

-        throw new NoSuchItemException();

-      size--;

-      int oldfront = front++;

-      if (front == array.Length) front = 0;

-      T retval = array[oldfront];

-      array[oldfront] = default(T);

-      if (ActiveEvents != 0)

-        raiseForRemove(retval);

-      return retval;

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item"></param>

-    public void Push(T item) //== Enqueue

-    {

-      if (!original)

-        throw new ReadOnlyCollectionException();

-      stamp++;

-      if (size == array.Length - 1) expand();

-      size++;

-      int oldback = back++;

-      if (back == array.Length) back = 0;

-      array[oldback] = item;

-      if (ActiveEvents != 0)

-        raiseForAdd(item);

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public T Pop()

-    {

-      if (!original)

-        throw new ReadOnlyCollectionException("Object is a non-updatable clone");

-      stamp++;

-      if (size == 0)

-        throw new NoSuchItemException();

-      size--;

-      back--;

-      if (back == -1) back = array.Length - 1;

-      T retval = array[back];

-      array[back] = default(T);

-      if (ActiveEvents != 0)

-        raiseForRemove(retval);

-      return retval;

-    }

-    #endregion

-

-    #region ICollectionValue<T> Members

-

-    //TODO: implement these with Array.Copy instead of relying on XxxBase:

-    /*

-        public void CopyTo(T[] a, int i)

-        {

-        }

-

-        public T[] ToArray()

-        {

-        }*/

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    [Tested]

-    public override T Choose()

-    {

-      if (size == 0)

-        throw new NoSuchItemException();

-      return array[front];

-    }

-

-    #endregion

-

-    #region IEnumerable<T> Members

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public override SCG.IEnumerator<T> GetEnumerator()

-    {

-      int stamp = this.stamp;

-      if (forwards)

-      {

-        int position = front;

-        int end = front <= back ? back : array.Length;

-        while (position < end)

-        {

-          if (stamp != this.stamp)

-            throw new CollectionModifiedException();

-          yield return array[position++];

-        }

-        if (front > back)

-        {

-          position = 0;

-          while (position < back)

-          {

-            if (stamp != this.stamp)

-              throw new CollectionModifiedException();

-            yield return array[position++];

-          }

-        }

-      }

-      else

-      {

-        int position = back - 1;

-        int end = front <= back ? front : 0;

-        while (position >= end)

-        {

-          if (stamp != this.stamp)

-            throw new CollectionModifiedException();

-          yield return array[position--];

-        }

-        if (front > back)

-        {

-          position = array.Length - 1;

-          while (position >= front)

-          {

-            if (stamp != this.stamp)

-              throw new CollectionModifiedException();

-            yield return array[position--];

-          }

-        }

-      }

-    }

-

-    #endregion

-

-    #region IDirectedCollectionValue<T> Members

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public override IDirectedCollectionValue<T> Backwards()

-    {

-      CircularQueue<T> retval = (CircularQueue<T>)MemberwiseClone();

-      retval.original = false;

-      retval.forwards = !forwards;

-      return retval;

-    }

-

-    #endregion

-

-    #region IDirectedEnumerable<T> Members

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    IDirectedEnumerable<T> IDirectedEnumerable<T>.Backwards()

-    {

-      return Backwards();

-    }

-

-    #endregion

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public virtual bool Check()

-    {

-      if (front < 0 || front >= array.Length || back < 0 || back >= array.Length ||

-          (front <= back && size != back - front) || (front > back && size != array.Length + back - front))

-      {

-        Console.WriteLine("Bad combination of (front,back,size,array.Length): ({0},{1},{2},{3})",

-            front, back, size, array.Length);

-        return false;

-      }

-      return true;

-    }

-  }

+/*
+ Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+ 
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+ 
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+*/
+
+using System;
+using System.Diagnostics;
+using SCG = System.Collections.Generic;
+namespace C5
+{
+  /// <summary>
+  /// 
+  /// </summary>
+  /// <typeparam name="T"></typeparam>
+  public class CircularQueue<T> : SequencedBase<T>, IQueue<T>, IStack<T>
+  {
+    #region Fields
+    /*
+        Invariant: the itemes in the queue ar the elements from front upwards, 
+        possibly wrapping around at the end of array, to back.
+
+        if front<=back then size = back - front + 1;
+        else size = array.Length + back - front + 1;
+
+        */
+    int front, back;
+    /// <summary>
+    /// The internal container array is doubled when necessary, but never shrinked.
+    /// </summary>
+    T[] array;
+    bool forwards = true, original = true;
+    #endregion
+
+    #region Events
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public override EventTypeEnum ListenableEvents { get { return EventTypeEnum.Basic; } }
+
+    #endregion
+
+    #region Util
+    void expand()
+    {
+      int newlength = 2 * array.Length;
+      T[] newarray = new T[newlength];
+
+      if (front <= back)
+        Array.Copy(array, front, newarray, 0, size);
+      else
+      {
+        int half = array.Length - front;
+        Array.Copy(array, front, newarray, 0, half);
+        Array.Copy(array, 0, newarray, half, size - half);
+      }
+
+      front = 0;
+      back = size;
+      array = newarray;
+    }
+
+    #endregion
+
+    #region Constructors
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public CircularQueue() : this(8) { }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="capacity"></param>
+    public CircularQueue(int capacity)
+      : base(EqualityComparer<T>.Default)
+    {
+      int newlength = 8;
+      while (newlength < capacity) newlength *= 2;
+      array = new T[newlength];
+    }
+
+    #endregion
+
+    #region IQueue<T> Members
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public virtual bool AllowsDuplicates { get { return true; } }
+
+    /// <summary>
+    /// Get the i'th item in the queue. The front of the queue is at index 0.
+    /// </summary>
+    /// <param name="i"></param>
+    /// <returns></returns>
+    public virtual T this[int i]
+    {
+      get
+      {
+        if (i < 0 || i >= size)
+          throw new IndexOutOfRangeException();
+        i = i + front;
+        //Bug fix by Steve Wallace 2006/02/10
+        return array[i >= array.Length ? i - array.Length : i];
+      }
+    }
+
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item"></param>
+    [Tested]
+    public virtual void Enqueue(T item)
+    {
+      if (!original)
+        throw new ReadOnlyCollectionException();
+      stamp++;
+      if (size == array.Length - 1) expand();
+      size++;
+      int oldback = back++;
+      if (back == array.Length) back = 0;
+      array[oldback] = item;
+      if (ActiveEvents != 0)
+        raiseForAdd(item);
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    [Tested]
+    public virtual T Dequeue()
+    {
+      if (!original)
+        throw new ReadOnlyCollectionException("Object is a non-updatable clone");
+      stamp++;
+      if (size == 0)
+        throw new NoSuchItemException();
+      size--;
+      int oldfront = front++;
+      if (front == array.Length) front = 0;
+      T retval = array[oldfront];
+      array[oldfront] = default(T);
+      if (ActiveEvents != 0)
+        raiseForRemove(retval);
+      return retval;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item"></param>
+    public void Push(T item) //== Enqueue
+    {
+      if (!original)
+        throw new ReadOnlyCollectionException();
+      stamp++;
+      if (size == array.Length - 1) expand();
+      size++;
+      int oldback = back++;
+      if (back == array.Length) back = 0;
+      array[oldback] = item;
+      if (ActiveEvents != 0)
+        raiseForAdd(item);
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public T Pop()
+    {
+      if (!original)
+        throw new ReadOnlyCollectionException("Object is a non-updatable clone");
+      stamp++;
+      if (size == 0)
+        throw new NoSuchItemException();
+      size--;
+      back--;
+      if (back == -1) back = array.Length - 1;
+      T retval = array[back];
+      array[back] = default(T);
+      if (ActiveEvents != 0)
+        raiseForRemove(retval);
+      return retval;
+    }
+    #endregion
+
+    #region ICollectionValue<T> Members
+
+    //TODO: implement these with Array.Copy instead of relying on XxxBase:
+    /*
+        public void CopyTo(T[] a, int i)
+        {
+        }
+
+        public T[] ToArray()
+        {
+        }*/
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    [Tested]
+    public override T Choose()
+    {
+      if (size == 0)
+        throw new NoSuchItemException();
+      return array[front];
+    }
+
+    #endregion
+
+    #region IEnumerable<T> Members
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public override SCG.IEnumerator<T> GetEnumerator()
+    {
+      int stamp = this.stamp;
+      if (forwards)
+      {
+        int position = front;
+        int end = front <= back ? back : array.Length;
+        while (position < end)
+        {
+          if (stamp != this.stamp)
+            throw new CollectionModifiedException();
+          yield return array[position++];
+        }
+        if (front > back)
+        {
+          position = 0;
+          while (position < back)
+          {
+            if (stamp != this.stamp)
+              throw new CollectionModifiedException();
+            yield return array[position++];
+          }
+        }
+      }
+      else
+      {
+        int position = back - 1;
+        int end = front <= back ? front : 0;
+        while (position >= end)
+        {
+          if (stamp != this.stamp)
+            throw new CollectionModifiedException();
+          yield return array[position--];
+        }
+        if (front > back)
+        {
+          position = array.Length - 1;
+          while (position >= front)
+          {
+            if (stamp != this.stamp)
+              throw new CollectionModifiedException();
+            yield return array[position--];
+          }
+        }
+      }
+    }
+
+    #endregion
+
+    #region IDirectedCollectionValue<T> Members
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public override IDirectedCollectionValue<T> Backwards()
+    {
+      CircularQueue<T> retval = (CircularQueue<T>)MemberwiseClone();
+      retval.original = false;
+      retval.forwards = !forwards;
+      return retval;
+    }
+
+    #endregion
+
+    #region IDirectedEnumerable<T> Members
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    IDirectedEnumerable<T> IDirectedEnumerable<T>.Backwards()
+    {
+      return Backwards();
+    }
+
+    #endregion
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public virtual bool Check()
+    {
+      if (front < 0 || front >= array.Length || back < 0 || back >= array.Length ||
+          (front <= back && size != back - front) || (front > back && size != array.Length + back - front))
+      {
+        Console.WriteLine("Bad combination of (front,back,size,array.Length): ({0},{1},{2},{3})",
+            front, back, size, array.Length);
+        return false;
+      }
+      return true;
+    }
+  }
 }
\ No newline at end of file
diff --git a/mcs/class/Mono.C5/C5/arrays/HashedArrayList.cs b/mcs/class/Mono.C5/C5/arrays/HashedArrayList.cs
index edc6b4c1797..87cd322320b 100644
--- a/mcs/class/Mono.C5/C5/arrays/HashedArrayList.cs
+++ b/mcs/class/Mono.C5/C5/arrays/HashedArrayList.cs
@@ -1,2638 +1,2638 @@
-

-/*

- Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft

- Permission is hereby granted, free of charge, to any person obtaining a copy

- of this software and associated documentation files (the "Software"), to deal

- in the Software without restriction, including without limitation the rights

- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

- copies of the Software, and to permit persons to whom the Software is

- furnished to do so, subject to the following conditions:

- 

- The above copyright notice and this permission notice shall be included in

- all copies or substantial portions of the Software.

- 

- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

- SOFTWARE.

-*/

-

-#define HASHINDEX

-

-using System;

-using System.Diagnostics;

-using SCG = System.Collections.Generic;

-namespace C5

-{

-  /// <summary>

-  /// A list collection based on a plain dynamic array data structure.

-  /// Expansion of the internal array is performed by doubling on demand. 

-  /// The internal array is only shrinked by the Clear method. 

-  ///

-  /// <i>When the FIFO property is set to false this class works fine as a stack of T.

-  /// When the FIFO property is set to true the class will function as a (FIFO) queue

-  /// but very inefficiently, use a LinkedList (<see cref="T:C5.LinkedList`1"/>) instead.</i>

-  /// </summary>

-  [Serializable]

-  public class HashedArrayList<T> : ArrayBase<T>, IList<T>, SCG.IList<T>

-#if HASHINDEX

-#else

-, IStack<T>, IQueue<T>

-#endif

-  {

-    #region Fields

-

-    /// <summary>

-    /// Has this list or view not been invalidated by some operation (by someone calling Dispose())

-    /// </summary>

-    bool isValid = true;

-

-    //TODO: wonder if we should save some memory on none-view situations by 

-    //      putting these three fields into a single ref field?

-    /// <summary>

-    /// The underlying list if we are a view, null else.

-    /// </summary>

-    HashedArrayList<T> underlying;

-    WeakViewList<HashedArrayList<T>> views;

-    WeakViewList<HashedArrayList<T>>.Node myWeakReference;

-

-    /// <summary>

-    /// The size of the underlying list.

-    /// </summary>

-    int underlyingsize { get { return (underlying ?? this).size; } }

-

-    /// <summary>

-    /// The underlying field of the FIFO property

-    /// </summary>

-    bool fIFO = false;

-

-#if HASHINDEX

-    HashSet<KeyValuePair<T, int>> itemIndex;

-#endif

-    #endregion

-    #region Events

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public override EventTypeEnum ListenableEvents { get { return underlying == null ? EventTypeEnum.All : EventTypeEnum.None; } }

-

-    /*

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event CollectionChangedHandler<T> CollectionChanged

-        {

-          add

-          {

-            if (underlying == null)

-              base.CollectionChanged += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.CollectionChanged -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event CollectionClearedHandler<T> CollectionCleared

-        {

-          add

-          {

-            if (underlying == null)

-              base.CollectionCleared += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.CollectionCleared -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event ItemsAddedHandler<T> ItemsAdded

-        {

-          add

-          {

-            if (underlying == null)

-              base.ItemsAdded += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.ItemsAdded -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event ItemInsertedHandler<T> ItemInserted

-        {

-          add

-          {

-            if (underlying == null)

-              base.ItemInserted += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.ItemInserted -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event ItemsRemovedHandler<T> ItemsRemoved

-        {

-          add

-          {

-            if (underlying == null)

-              base.ItemsRemoved += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.ItemsRemoved -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-        /// <summary>

-        /// 

-        /// </summary>

-        /// <value></value>

-        public override event ItemRemovedAtHandler<T> ItemRemovedAt

-        {

-          add

-          {

-            if (underlying == null)

-              base.ItemRemovedAt += value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-          remove

-          {

-            if (underlying == null)

-              base.ItemRemovedAt -= value;

-            else

-              throw new UnlistenableEventException("Can't listen to a view");

-          }

-        }

-

-          */

-

-    #endregion

-    #region Util

-

-    bool equals(T i1, T i2) { return itemequalityComparer.Equals(i1, i2); }

-

-    /// <summary>

-    /// Increment or decrement the private size fields

-    /// </summary>

-    /// <param name="delta">Increment (with sign)</param>

-    void addtosize(int delta)

-    {

-      size += delta;

-      if (underlying != null)

-        underlying.size += delta;

-    }

-

-    #region Array handling

-    /// <summary>

-    /// Double the size of the internal array.

-    /// </summary>

-    protected override void expand()

-    { expand(2 * array.Length, underlyingsize); }

-

-

-    /// <summary>

-    /// Expand the internal array, resetting the index of the first unused element.

-    /// </summary>

-    /// <param name="newcapacity">The new capacity (will be rouded upwards to a power of 2).</param>

-    /// <param name="newsize">The new count of </param>

-    protected override void expand(int newcapacity, int newsize)

-    {

-      if (underlying != null)

-        underlying.expand(newcapacity, newsize);

-      else

-      {

-        base.expand(newcapacity, newsize);

-        if (views != null)

-          foreach (HashedArrayList<T> v in views)

-            v.array = array;

-      }

-    }

-

-    #endregion

-

-    #region Checks

-    /// <summary>

-    /// Check if it is valid to perform updates and increment stamp if so.

-    /// </summary>

-    /// <exception cref="ViewDisposedException"> If check fails by this list being a disposed view.</exception>

-    /// <exception cref="ReadOnlyCollectionException"> If check fails by this being a read only list.</exception>

-    protected override void updatecheck()

-    {

-      validitycheck();

-      base.updatecheck();

-      if (underlying != null)

-        underlying.stamp++;

-    }

-

-

-    /// <summary>

-    /// Check if we are a view that the underlying list has only been updated through us.

-    /// <para>This method should be called from enumerators etc to guard against 

-    /// modification of the base collection.</para>

-    /// </summary>

-    /// <exception cref="ViewDisposedException"> if check fails.</exception>

-    void validitycheck()

-    {

-      if (!isValid)

-        throw new ViewDisposedException();

-    }

-

-

-    /// <summary>

-    /// Check that the list has not been updated since a particular time.

-    /// <para>To be used by enumerators and range </para>

-    /// </summary>

-    /// <exception cref="ViewDisposedException"> If check fails by this list being a disposed view.</exception>

-    /// <exception cref="CollectionModifiedException">If the list *has* beeen updated since that  time..</exception>

-    /// <param name="stamp">The stamp indicating the time.</param>

-    protected override void modifycheck(int stamp)

-    {

-      validitycheck();

-      if (this.stamp != stamp)

-        throw new CollectionModifiedException();

-    }

-

-    #endregion

-

-    #region Searching

-

-    /// <summary>

-    /// Internal version of IndexOf without modification checks.

-    /// </summary>

-    /// <param name="item">Item to look for</param>

-    /// <returns>The index of first occurrence</returns>

-    int indexOf(T item)

-    {

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item);

-      if (itemIndex.Find(ref p) && p.Value >= offset && p.Value < offset + size)

-        return p.Value - offset;

-#else

-      for (int i = 0; i < size; i++)

-        if (equals(item, array[offset + i]))

-          return i;

-#endif

-      return ~size;

-    }

-

-    /// <summary>

-    /// Internal version of LastIndexOf without modification checks.

-    /// </summary>

-    /// <param name="item">Item to look for</param>

-    /// <returns>The index of last occurrence</returns>

-    int lastIndexOf(T item)

-    {

-#if HASHINDEX

-      return indexOf(item);

-#else

-      for (int i = size - 1; i >= 0; i--)

-        if (equals(item, array[offset + i]))

-          return i;

-      return ~size;

-#endif

-    }

-    #endregion

-

-    #region Inserting

-

-#if HASHINDEX

-    /// <summary>

-    /// Internal version of Insert with no modification checks.

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException"> if item already in list.</exception>

-    /// <param name="i">Index to insert at</param>

-    /// <param name="item">Item to insert</param>

-#else

-    /// <summary>

-    /// Internal version of Insert with no modification checks.

-    /// </summary>

-    /// <param name="i">Index to insert at</param>

-    /// <param name="item">Item to insert</param>

-#endif

-    protected override void insert(int i, T item)

-    {

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, offset + i);

-      if (itemIndex.FindOrAdd(ref p))

-        throw new DuplicateNotAllowedException("Item already in indexed list: " + item);

-#endif

-      baseinsert(i, item);

-#if HASHINDEX

-      reindex(i + offset + 1);

-#endif

-    }

-

-    private void baseinsert(int i, T item)

-    {

-      if (underlyingsize == array.Length)

-        expand();

-      i += offset;

-      if (i < underlyingsize)

-        Array.Copy(array, i, array, i + 1, underlyingsize - i);

-      array[i] = item;

-      addtosize(1);

-      fixViewsAfterInsert(1, i);

-    }

-    #endregion

-

-    #region Removing

-

-    /// <summary>

-    /// Internal version of RemoveAt with no modification checks.

-    /// </summary>

-    /// <param name="i">Index to remove at</param>

-    /// <returns>The removed item</returns>

-    T removeAt(int i)

-    {

-      i += offset;

-      fixViewsBeforeSingleRemove(i);

-      T retval = array[i];

-      addtosize(-1);

-      if (underlyingsize > i)

-        Array.Copy(array, i + 1, array, i, underlyingsize - i);

-      array[underlyingsize] = default(T);

-#if HASHINDEX

-      itemIndex.Remove(new KeyValuePair<T, int>(retval));

-      reindex(i);

-#endif

-      return retval;

-    }

-    #endregion

-

-    #region Indexing

-

-#if HASHINDEX

-    private void reindex(int start) { reindex(start, underlyingsize); }

-

-    private void reindex(int start, int end)

-    {

-      for (int j = start; j < end; j++)

-        itemIndex.UpdateOrAdd(new KeyValuePair<T, int>(array[j], j));

-    }

-#endif

-    #endregion

-

-    #region fixView utilities

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="added">The actual number of inserted nodes</param>

-    /// <param name="realInsertionIndex"></param>

-    void fixViewsAfterInsert(int added, int realInsertionIndex)

-    {

-      if (views != null)

-        foreach (HashedArrayList<T> view in views)

-        {

-          if (view != this)

-          {

-            if (view.offset < realInsertionIndex && view.offset + view.size > realInsertionIndex)

-              view.size += added;

-            if (view.offset > realInsertionIndex || (view.offset == realInsertionIndex && view.size > 0))

-              view.offset += added;

-          }

-        }

-    }

-

-    void fixViewsBeforeSingleRemove(int realRemovalIndex)

-    {

-      if (views != null)

-        foreach (HashedArrayList<T> view in views)

-        {

-          if (view != this)

-          {

-            if (view.offset <= realRemovalIndex && view.offset + view.size > realRemovalIndex)

-              view.size--;

-            if (view.offset > realRemovalIndex)

-              view.offset--;

-          }

-        }

-    }

-

-    /// <summary>

-    /// Fix offsets and sizes of other views before removing an interval from this 

-    /// </summary>

-    /// <param name="start">the start of the interval relative to the array/underlying</param>

-    /// <param name="count"></param>

-    void fixViewsBeforeRemove(int start, int count)

-    {

-      int clearend = start + count - 1;

-      if (views != null)

-        foreach (HashedArrayList<T> view in views)

-        {

-          if (view == this)

-            continue;

-          int viewoffset = view.offset, viewend = viewoffset + view.size - 1;

-          if (start < viewoffset)

-          {

-            if (clearend < viewoffset)

-              view.offset = viewoffset - count;

-            else

-            {

-              view.offset = start;

-              view.size = clearend < viewend ? viewend - clearend : 0;

-            }

-          }

-          else if (start <= viewend)

-            view.size = clearend <= viewend ? view.size - count : start - viewoffset;

-        }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="otherOffset"></param>

-    /// <param name="otherSize"></param>

-    /// <returns>The position of View(otherOffset, otherSize) wrt. this view</returns>

-    MutualViewPosition viewPosition(int otherOffset, int otherSize)

-    {

-      int end = offset + size, otherEnd = otherOffset + otherSize;

-      if (otherOffset >= end || otherEnd <= offset)

-        return MutualViewPosition.NonOverlapping;

-      if (size == 0 || (otherOffset <= offset && end <= otherEnd))

-        return MutualViewPosition.Contains;

-      if (otherSize == 0 || (offset <= otherOffset && otherEnd <= end))

-        return MutualViewPosition.ContainedIn;

-      return MutualViewPosition.Overlapping;

-    }

-

-    //TODO: make version that fits the new, more forgiving rules for disposing

-    void disposeOverlappingViews(bool reverse)

-    {

-      if (views != null)

-        foreach (HashedArrayList<T> view in views)

-        {

-          if (view != this)

-          {

-            switch (viewPosition(view.offset, view.size))

-            {

-              case MutualViewPosition.ContainedIn:

-                if (reverse)

-                  view.offset = 2 * offset + size - view.size - view.offset;

-                else

-                  view.Dispose();

-                break;

-              case MutualViewPosition.Overlapping:

-                view.Dispose();

-                break;

-              case MutualViewPosition.Contains:

-              case MutualViewPosition.NonOverlapping:

-                break;

-            }

-          }

-        }

-    }

-    #endregion

-

-    #endregion

-

-    #region Position, PositionComparer and ViewHandler nested types

-    class PositionComparer : SCG.IComparer<Position>

-    {

-      public int Compare(Position a, Position b)

-      {

-        return a.index.CompareTo(b.index);

-      }

-    }

-    /// <summary>

-    /// During RemoveAll, we need to cache the original endpoint indices of views (??? also for HashedArrayList?)

-    /// </summary>

-    struct Position

-    {

-      public readonly HashedArrayList<T> view;

-      public readonly int index;

-      public Position(HashedArrayList<T> view, bool left)

-      {

-        this.view = view;

-        index = left ? view.offset : view.offset + view.size - 1;

-      }

-      public Position(int index) { this.index = index; view = null; }

-    }

-

-    /// <summary>

-    /// Handle the update of (other) views during a multi-remove operation.

-    /// </summary>

-    struct ViewHandler

-    {

-      HashedArrayList<Position> leftEnds;

-      HashedArrayList<Position> rightEnds;

-      int leftEndIndex, rightEndIndex;

-      internal readonly int viewCount;

-      internal ViewHandler(HashedArrayList<T> list)

-      {

-        leftEndIndex = rightEndIndex = viewCount = 0;

-        leftEnds = rightEnds = null;

-        if (list.views != null)

-          foreach (HashedArrayList<T> v in list.views)

-            if (v != list)

-            {

-              if (leftEnds == null)

-              {

-                leftEnds = new HashedArrayList<Position>();

-                rightEnds = new HashedArrayList<Position>();

-              }

-              leftEnds.Add(new Position(v, true));

-              rightEnds.Add(new Position(v, false));

-            }

-        if (leftEnds == null)

-          return;

-        viewCount = leftEnds.Count;

-        leftEnds.Sort(new PositionComparer());

-        rightEnds.Sort(new PositionComparer());

-      }

-      /// <summary>

-      /// This is to be called with realindex pointing to the first node to be removed after a (stretch of) node that was not removed

-      /// </summary>

-      /// <param name="removed"></param>

-      /// <param name="realindex"></param>

-      internal void skipEndpoints(int removed, int realindex)

-      {

-        if (viewCount > 0)

-        {

-          Position endpoint;

-          while (leftEndIndex < viewCount && (endpoint = leftEnds[leftEndIndex]).index <= realindex)

-          {

-            HashedArrayList<T> view = endpoint.view;

-            view.offset = view.offset - removed;

-            view.size += removed;

-            leftEndIndex++;

-          }

-          while (rightEndIndex < viewCount && (endpoint = rightEnds[rightEndIndex]).index < realindex)

-          {

-            endpoint.view.size -= removed;

-            rightEndIndex++;

-          }

-        }

-      }

-      internal void updateViewSizesAndCounts(int removed, int realindex)

-      {

-        if (viewCount > 0)

-        {

-          Position endpoint;

-          while (leftEndIndex < viewCount && (endpoint = leftEnds[leftEndIndex]).index <= realindex)

-          {

-            HashedArrayList<T> view = endpoint.view;

-            view.offset = view.Offset - removed;

-            view.size += removed;

-            leftEndIndex++;

-          }

-          while (rightEndIndex < viewCount && (endpoint = rightEnds[rightEndIndex]).index < realindex)

-          {

-            endpoint.view.size -= removed;

-            rightEndIndex++;

-          }

-        }

-      }

-    }

-    #endregion

-

-    #region Constructors

-    /// <summary>

-    /// Create an array list with default item equalityComparer and initial capacity 8 items.

-    /// </summary>

-    public HashedArrayList() : this(8) { }

-

-

-    /// <summary>

-    /// Create an array list with external item equalityComparer and initial capacity 8 items.

-    /// </summary>

-    /// <param name="itemequalityComparer">The external item equalityComparer</param>

-    public HashedArrayList(SCG.IEqualityComparer<T> itemequalityComparer) : this(8, itemequalityComparer) { }

-

-

-    /// <summary>

-    /// Create an array list with default item equalityComparer and prescribed initial capacity.

-    /// </summary>

-    /// <param name="capacity">The prescribed capacity</param>

-    public HashedArrayList(int capacity) : this(capacity, EqualityComparer<T>.Default) { }

-

-

-    /// <summary>

-    /// Create an array list with external item equalityComparer and prescribed initial capacity.

-    /// </summary>

-    /// <param name="capacity">The prescribed capacity</param>

-    /// <param name="itemequalityComparer">The external item equalityComparer</param>

-    public HashedArrayList(int capacity, SCG.IEqualityComparer<T> itemequalityComparer)

-      : base(capacity, itemequalityComparer)

-    {

-#if HASHINDEX

-      itemIndex = new HashSet<KeyValuePair<T, int>>(new KeyValuePairEqualityComparer<T, int>(itemequalityComparer));

-#endif

-    }

-

-    #endregion

-

-    #region IList<T> Members

-

-    /// <summary>

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <value>The first item in this list.</value>

-    [Tested]

-    public virtual T First

-    {

-      [Tested]

-      get

-      {

-        validitycheck();

-        if (size == 0)

-          throw new NoSuchItemException();

-

-        return array[offset];

-      }

-    }

-

-

-    /// <summary>

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <value>The last item in this list.</value>

-    [Tested]

-    public virtual T Last

-    {

-      [Tested]

-      get

-      {

-        validitycheck();

-        if (size == 0)

-          throw new NoSuchItemException();

-

-        return array[offset + size - 1];

-      }

-    }

-

-

-    /// <summary>

-    /// Since <code>Add(T item)</code> always add at the end of the list,

-    /// this describes if list has FIFO or LIFO semantics.

-    /// </summary>

-    /// <value>True if the <code>Remove()</code> operation removes from the

-    /// start of the list, false if it removes from the end. The default for a new array list is false.</value>

-    [Tested]

-    public virtual bool FIFO

-    {

-      [Tested]

-      get { validitycheck(); return fIFO; }

-      [Tested]

-      set { updatecheck(); fIFO = value; }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    public virtual bool IsFixedSize

-    {

-      get { validitycheck(); return false; }

-    }

-

-

-#if HASHINDEX

-    /// <summary>

-    /// On this list, this indexer is read/write.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt;= the size of the collection.</exception>

-    /// <exception cref="DuplicateNotAllowedException"> By the get operation

-    /// if the item already is present somewhere else in the list.</exception>

-    /// <value>The index'th item of this list.</value>

-    /// <param name="index">The index of the item to fetch or store.</param>

-#else

-    /// <summary>

-    /// On this list, this indexer is read/write.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt;= the size of the collection.</exception>

-    /// <value>The index'th item of this list.</value>

-    /// <param name="index">The index of the item to fetch or store.</param>

-#endif

-    [Tested]

-    public virtual T this[int index]

-    {

-      [Tested]

-      get

-      {

-        validitycheck();

-        if (index < 0 || index >= size)

-          throw new IndexOutOfRangeException();

-

-        return array[offset + index];

-      }

-      [Tested]

-      set

-      {

-        updatecheck();

-        if (index < 0 || index >= size)

-          throw new IndexOutOfRangeException();

-        index += offset;

-        T item = array[index];

-#if HASHINDEX

-        KeyValuePair<T, int> p = new KeyValuePair<T, int>(value, index);

-        if (itemequalityComparer.Equals(value, item))

-        {

-          array[index] = value;

-          itemIndex.Update(p);

-        }

-        else if (!itemIndex.FindOrAdd(ref p))

-        {

-          itemIndex.Remove(new KeyValuePair<T, int>(item));

-          array[index] = value;

-        }

-        else

-          throw new DuplicateNotAllowedException("Item already in indexed list");

-#else

-        array[index] = value;

-#endif

-        (underlying ?? this).raiseForSetThis(index, value, item);

-      }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public virtual Speed IndexingSpeed { get { return Speed.Constant; } }

-

-#if HASHINDEX

-    /// <summary>

-    /// Insert an item at a specific index location in this list. 

-    ///</summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt; the size of the collection. </exception>

-    /// <exception cref="DuplicateNotAllowedException"> 

-    /// If the item is already present in the list.</exception>

-    /// <param name="index">The index at which to insert.</param>

-    /// <param name="item">The item to insert.</param>

-#else

-    /// <summary>

-    /// Insert an item at a specific index location in this list. 

-    ///</summary>

-    /// <exception cref="IndexOutOfRangeException"> if i is negative or

-    /// &gt; the size of the collection. </exception>

-    /// <param name="index">The index at which to insert.</param>

-    /// <param name="item">The item to insert.</param>

-#endif

-    [Tested]

-    public virtual void Insert(int index, T item)

-    {

-      updatecheck();

-      if (index < 0 || index > size)

-        throw new IndexOutOfRangeException();

-

-      insert(index, item);

-      (underlying ?? this).raiseForInsert(index + offset, item);

-    }

-

-    /// <summary>

-    /// Insert an item at the end of a compatible view, used as a pointer.

-    /// <para>The <code>pointer</code> must be a view on the same list as

-    /// <code>this</code> and the endpoitn of <code>pointer</code> must be

-    /// a valid insertion point of <code>this</code></para>

-    /// </summary>

-    /// <exception cref="IncompatibleViewException">If <code>pointer</code> 

-    /// is not a view on or the same list as <code>this</code></exception>

-    /// <exception cref="IndexOutOfRangeException"><b>??????</b> if the endpoint of 

-    ///  <code>pointer</code> is not inside <code>this</code></exception>

-    /// <exception cref="DuplicateNotAllowedException"> if the list has

-    /// <code>AllowsDuplicates==false</code> and the item is 

-    /// already in the list.</exception>

-    /// <param name="pointer"></param>

-    /// <param name="item"></param>

-    public void Insert(IList<T> pointer, T item)

-    {

-      if ((pointer == null) || ((pointer.Underlying ?? pointer) != (underlying ?? this)))

-        throw new IncompatibleViewException();

-      Insert(pointer.Offset + pointer.Count - Offset, item);

-    }

-

-#if HASHINDEX

-    /// <summary>

-    /// Insert into this list all items from an enumerable collection starting 

-    /// at a particular index.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt; the size of the collection.</exception>

-    /// <exception cref="DuplicateNotAllowedException"> If <code>items</code> 

-    /// contains duplicates or some item already  present in the list.</exception>

-    /// <param name="index">Index to start inserting at</param>

-    /// <param name="items">Items to insert</param>

-#else

-    /// <summary>

-    /// Insert into this list all items from an enumerable collection starting 

-    /// at a particular index.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt; the size of the collection.</exception>

-    /// <param name="index">Index to start inserting at</param>

-    /// <param name="items">Items to insert</param>

-    /// <typeparam name="U"></typeparam>

-#endif

-    [Tested]

-    public virtual void InsertAll<U>(int index, SCG.IEnumerable<U> items) where U : T

-    {

-      updatecheck();

-      if (index < 0 || index > size)

-        throw new IndexOutOfRangeException();

-      index += offset;

-      int toadd = EnumerableBase<U>.countItems(items);

-      if (toadd == 0)

-        return;

-      if (toadd + underlyingsize > array.Length)

-        expand(toadd + underlyingsize, underlyingsize);

-      if (underlyingsize > index)

-        Array.Copy(array, index, array, index + toadd, underlyingsize - index);

-      int i = index;

-      try

-      {

-

-        foreach (T item in items)

-        {

-#if HASHINDEX

-          KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, i);

-          if (itemIndex.FindOrAdd(ref p))

-            throw new DuplicateNotAllowedException("Item already in indexed list");

-#endif

-          array[i++] = item;

-        }

-      }

-      finally

-      {

-        int added = i - index;

-        if (added < toadd)

-        {

-          Array.Copy(array, index + toadd, array, i, underlyingsize - index);

-          Array.Clear(array, underlyingsize + added, toadd - added);

-        }

-        if (added > 0)

-        {

-          addtosize(added);

-#if HASHINDEX

-          reindex(i);

-#endif

-          fixViewsAfterInsert(added, index);

-          (underlying ?? this).raiseForInsertAll(index, added);

-        }

-      }

-    }

-    private void raiseForInsertAll(int index, int added)

-    {

-      if (ActiveEvents != 0)

-      {

-        if ((ActiveEvents & (EventTypeEnum.Added | EventTypeEnum.Inserted)) != 0)

-          for (int j = index; j < index + added; j++)

-          {

-            raiseItemInserted(array[j], j);

-            raiseItemsAdded(array[j], 1);

-          }

-        raiseCollectionChanged();

-      }

-    }

-

-#if HASHINDEX

-    /// <summary>

-    /// Insert an item at the front of this list;

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException">If the item is already in the list</exception>

-    /// <param name="item">The item to insert.</param>

-#else

-    /// <summary>

-    /// Insert an item at the front of this list;

-    /// </summary>

-    /// <param name="item">The item to insert.</param>

-#endif

-    [Tested]

-    public virtual void InsertFirst(T item)

-    {

-      updatecheck();

-      insert(0, item);

-      (underlying ?? this).raiseForInsert(offset, item);

-    }

-

-

-#if HASHINDEX

-    /// <summary>

-    /// Insert an item at the back of this list.

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException">If the item is already in the list</exception>

-    /// <param name="item">The item to insert.</param>

-#else

-    /// <summary>

-    /// Insert an item at the back of this list.

-    /// </summary>

-    /// <param name="item">The item to insert.</param>

-#endif

-    [Tested]

-    public virtual void InsertLast(T item)

-    {

-      updatecheck();

-      insert(size, item);

-      (underlying ?? this).raiseForInsert(size - 1 + offset, item);

-    }

-

-

-    //NOTE: if the filter throws an exception, no result will be returned.

-    /// <summary>

-    /// Create a new list consisting of the items of this list satisfying a 

-    /// certain predicate.

-    /// <para>The new list will be of type HashedArrayList</para>

-    /// </summary>

-    /// <param name="filter">The filter delegate defining the predicate.</param>

-    /// <returns>The new list.</returns>

-    [Tested]

-    public virtual IList<T> FindAll(Fun<T, bool> filter)

-    {

-      validitycheck();

-      int stamp = this.stamp;

-      HashedArrayList<T> res = new HashedArrayList<T>(itemequalityComparer);

-      int j = 0, rescap = res.array.Length;

-      for (int i = 0; i < size; i++)

-      {

-        T a = array[offset + i];

-        bool found = filter(a);

-        modifycheck(stamp);

-        if (found)

-        {

-          if (j == rescap) res.expand(rescap = 2 * rescap, j);

-          res.array[j++] = a;

-        }

-      }

-      res.size = j;

-#if HASHINDEX

-      res.reindex(0);

-#endif

-      return res;

-    }

-

-

-#if HASHINDEX

-    /// <summary>

-    /// Create a new list consisting of the results of mapping all items of this

-    /// list. The new list will use the default item equalityComparer for the item type V.

-    /// <para>The new list will be of type HashedArrayList</para>

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException">If <code>mapper</code>

-    /// creates duplicates</exception>

-    /// <typeparam name="V">The type of items of the new list</typeparam>

-    /// <param name="mapper">The delegate defining the map.</param>

-    /// <returns>The new list.</returns>

-#else

-    /// <summary>

-    /// Create a new list consisting of the results of mapping all items of this

-    /// list. The new list will use the default item equalityComparer for the item type V.

-    /// <para>The new list will be of type HashedArrayList</para>

-    /// </summary>

-    /// <typeparam name="V">The type of items of the new list</typeparam>

-    /// <param name="mapper">The delegate defining the map.</param>

-    /// <returns>The new list.</returns>

-#endif

-    [Tested]

-    public virtual IList<V> Map<V>(Fun<T, V> mapper)

-    {

-      validitycheck();

-

-      HashedArrayList<V> res = new HashedArrayList<V>(size);

-

-      return map<V>(mapper, res);

-    }

-

-#if HASHINDEX

-    /// <summary>

-    /// Create a new list consisting of the results of mapping all items of this

-    /// list. The new list will use a specified item equalityComparer for the item type.

-    /// <para>The new list will be of type HashedArrayList</para>

-    /// </summary>

-    /// <exception cref="DuplicateNotAllowedException">If <code>mapper</code>

-    /// creates duplicates</exception>

-    /// <typeparam name="V">The type of items of the new list</typeparam>

-    /// <param name="mapper">The delegate defining the map.</param>

-    /// <param name="itemequalityComparer">The item equalityComparer to use for the new list</param>

-    /// <returns>The new list.</returns>

-#else

-    /// <summary>

-    /// Create a new list consisting of the results of mapping all items of this

-    /// list. The new list will use a specified item equalityComparer for the item type.

-    /// <para>The new list will be of type HashedArrayList</para>

-    /// </summary>

-    /// <typeparam name="V">The type of items of the new list</typeparam>

-    /// <param name="mapper">The delegate defining the map.</param>

-    /// <param name="itemequalityComparer">The item equalityComparer to use for the new list</param>

-    /// <returns>The new list.</returns>

-#endif

-    public virtual IList<V> Map<V>(Fun<T, V> mapper, SCG.IEqualityComparer<V> itemequalityComparer)

-    {

-      validitycheck();

-

-      HashedArrayList<V> res = new HashedArrayList<V>(size, itemequalityComparer);

-

-      return map<V>(mapper, res);

-    }

-

-    private IList<V> map<V>(Fun<T, V> mapper, HashedArrayList<V> res)

-    {

-      int stamp = this.stamp;

-      if (size > 0)

-        for (int i = 0; i < size; i++)

-        {

-          V mappeditem = mapper(array[offset + i]);

-          modifycheck(stamp);

-#if HASHINDEX

-          KeyValuePair<V, int> p = new KeyValuePair<V, int>(mappeditem, i);

-          if (res.itemIndex.FindOrAdd(ref p))

-            throw new ArgumentException("Mapped item already in indexed list");

-#endif

-          res.array[i] = mappeditem;

-        }

-      res.size = size;

-      return res;

-    }

-

-    /// <summary>

-    /// Remove one item from the list: from the front if <code>FIFO</code>

-    /// is true, else from the back.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public virtual T Remove()

-    {

-      updatecheck();

-      if (size == 0)

-        throw new NoSuchItemException("List is empty");

-

-      T item = removeAt(fIFO ? 0 : size - 1);

-      (underlying ?? this).raiseForRemove(item);

-      return item;

-    }

-

-    /// <summary>

-    /// Remove one item from the fromnt of the list.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public virtual T RemoveFirst()

-    {

-      updatecheck();

-      if (size == 0)

-        throw new NoSuchItemException("List is empty");

-

-      T item = removeAt(0);

-      (underlying ?? this).raiseForRemoveAt(offset, item);

-      return item;

-    }

-

-

-    /// <summary>

-    /// Remove one item from the back of the list.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public virtual T RemoveLast()

-    {

-      updatecheck();

-      if (size == 0)

-        throw new NoSuchItemException("List is empty");

-

-      T item = removeAt(size - 1);

-      (underlying ?? this).raiseForRemoveAt(size + offset, item);

-      return item;

-    }

-

-    /// <summary>

-    /// Create a list view on this list. 

-    /// </summary>

-    /// <exception cref="ArgumentOutOfRangeException"> if the start or count is negative

-    /// or the range does not fit within list.</exception>

-    /// <param name="start">The index in this list of the start of the view.</param>

-    /// <param name="count">The size of the view.</param>

-    /// <returns>The new list view.</returns>

-    [Tested]

-    public virtual IList<T> View(int start, int count)

-    {

-      validitycheck();

-      checkRange(start, count);

-      if (views == null)

-        views = new WeakViewList<HashedArrayList<T>>();

-      HashedArrayList<T> retval = (HashedArrayList<T>)MemberwiseClone();

-

-

-      retval.underlying = underlying != null ? underlying : this;

-      retval.offset = start + offset;

-      retval.size = count;

-      retval.myWeakReference = views.Add(retval);

-      return retval;

-    }

-

-    /// <summary>

-    /// Create a list view on this list containing the (first) occurrence of a particular item.

-    /// <para>Returns <code>null</code> if the item is not in this list.</para>

-    /// </summary>

-    /// <param name="item">The item to find.</param>

-    /// <returns>The new list view.</returns>

-    [Tested]

-    public virtual IList<T> ViewOf(T item)

-    {

-      int index = indexOf(item);

-      if (index < 0)

-        return null;

-      return View(index, 1);

-    }

-

-

-    /// <summary>

-    /// Create a list view on this list containing the last occurrence of a particular item. 

-    /// <para>Returns <code>null</code> if the item is not in this list.</para>

-    /// </summary>

-    /// <param name="item">The item to find.</param>

-    /// <returns>The new list view.</returns>

-    [Tested]

-    public virtual IList<T> LastViewOf(T item)

-    {

-      int index = lastIndexOf(item);

-      if (index < 0)

-        return null;

-      return View(index, 1);

-    }

-

-    /// <summary>

-    /// Null if this list is not a view.

-    /// </summary>

-    /// <value>Underlying list for view.</value>

-    [Tested]

-    public virtual IList<T> Underlying { [Tested]get { return underlying; } }

-

-

-    /// <summary>

-    /// </summary>

-    /// <value>Offset for this list view or 0 for an underlying list.</value>

-    [Tested]

-    public virtual int Offset { [Tested]get { return offset; } }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public virtual bool IsValid { get { return isValid; } }

-

-    /// <summary>

-    /// Slide this list view along the underlying list.

-    /// </summary>

-    /// <exception cref="NotAViewException"> if this list is not a view.</exception>

-    /// <exception cref="ArgumentOutOfRangeException"> if the operation

-    /// would bring either end of the view outside the underlying list.</exception>

-    /// <param name="offset">The signed amount to slide: positive to slide

-    /// towards the end.</param>

-    [Tested]

-    public virtual IList<T> Slide(int offset)

-    {

-      if (!TrySlide(offset, size))

-        throw new ArgumentOutOfRangeException();

-      return this;

-    }

-

-

-    /// <summary>

-    /// Slide this list view along the underlying list, changing its size.

-    /// </summary>

-    /// <exception cref="NotAViewException"> if this list is not a view.</exception>

-    /// <exception cref="ArgumentOutOfRangeException"> if the operation

-    /// would bring either end of the view outside the underlying list.</exception>

-    /// <param name="offset">The signed amount to slide: positive to slide

-    /// towards the end.</param>

-    /// <param name="size">The new size of the view.</param>

-    [Tested]

-    public virtual IList<T> Slide(int offset, int size)

-    {

-      if (!TrySlide(offset, size))

-        throw new ArgumentOutOfRangeException();

-      return this;

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <exception cref="NotAViewException"> if this list is not a view.</exception>

-    /// <param name="offset"></param>

-    /// <returns></returns>

-    [Tested]

-    public virtual bool TrySlide(int offset)

-    {

-      return TrySlide(offset, size);

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <exception cref="NotAViewException"> if this list is not a view.</exception>

-    /// <param name="offset"></param>

-    /// <param name="size"></param>

-    /// <returns></returns>

-    [Tested]

-    public virtual bool TrySlide(int offset, int size)

-    {

-      updatecheck();

-      if (underlying == null)

-        throw new NotAViewException("Not a view");

-

-      int newoffset = this.offset + offset;

-      int newsize = size;

-

-      if (newoffset < 0 || newsize < 0 || newoffset + newsize > underlyingsize)

-        return false;

-

-      this.offset = newoffset;

-      this.size = newsize;

-      return true;

-    }

-

-    /// <summary>

-    /// 

-    /// <para>Returns null if <code>otherView</code> is strictly to the left of this view</para>

-    /// </summary>

-    /// <param name="otherView"></param>

-    /// <exception cref="IncompatibleViewException">If otherView does not have the same underlying list as this</exception>

-    /// <returns></returns>

-    public virtual IList<T> Span(IList<T> otherView)

-    {

-      if ((otherView == null) || ((otherView.Underlying ?? otherView) != (underlying ?? this)))

-        throw new IncompatibleViewException();

-      if (otherView.Offset + otherView.Count - Offset < 0)

-        return null;

-      return (underlying ?? this).View(Offset, otherView.Offset + otherView.Count - Offset);

-    }

-

-    /// <summary>

-    /// Reverst the list so the items are in the opposite sequence order.

-    /// </summary>

-    [Tested]

-    public virtual void Reverse()

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      for (int i = 0, length = size / 2, end = offset + size - 1; i < length; i++)

-      {

-        T swap = array[offset + i];

-

-        array[offset + i] = array[end - i];

-        array[end - i] = swap;

-      }

-#if HASHINDEX

-      reindex(offset, offset + size);

-#endif

-      //TODO: be more forgiving wrt. disposing

-      disposeOverlappingViews(true);

-      (underlying ?? this).raiseCollectionChanged();

-    }

-

-    /// <summary>

-    /// Check if this list is sorted according to the default sorting order

-    /// for the item type T, as defined by the <see cref="T:C5.Comparer`1"/> class 

-    /// </summary>

-    /// <exception cref="NotComparableException">if T is not comparable</exception>

-    /// <returns>True if the list is sorted, else false.</returns>

-    [Tested]

-    public bool IsSorted() { return IsSorted(Comparer<T>.Default); }

-

-    /// <summary>

-    /// Check if this list is sorted according to a specific sorting order.

-    /// </summary>

-    /// <param name="c">The comparer defining the sorting order.</param>

-    /// <returns>True if the list is sorted, else false.</returns>

-    [Tested]

-    public virtual bool IsSorted(SCG.IComparer<T> c)

-    {

-      validitycheck();

-      for (int i = offset + 1, end = offset + size; i < end; i++)

-        if (c.Compare(array[i - 1], array[i]) > 0)

-          return false;

-

-      return true;

-    }

-

-    /// <summary>

-    /// Sort the items of the list according to the default sorting order

-    /// for the item type T, as defined by the Comparer[T] class 

-    /// (<see cref="T:C5.Comparer`1"/>).

-    /// </summary>

-    /// <exception cref="InvalidOperationException">if T is not comparable</exception>

-    public virtual void Sort()

-    {

-      Sort(Comparer<T>.Default);

-    }

-

-

-    /// <summary>

-    /// Sort the items of the list according to a specific sorting order.

-    /// </summary>

-    /// <param name="comparer">The comparer defining the sorting order.</param>

-    [Tested]

-    public virtual void Sort(SCG.IComparer<T> comparer)

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      Sorting.IntroSort<T>(array, offset, size, comparer);

-      disposeOverlappingViews(false);

-#if HASHINDEX

-      reindex(offset, offset + size);

-#endif

-      (underlying ?? this).raiseCollectionChanged();

-    }

-

-

-    /// <summary>

-    /// Randomly shuffle the items of this list. 

-    /// </summary>

-    public virtual void Shuffle() { Shuffle(new C5Random()); }

-

-

-    /// <summary>

-    /// Shuffle the items of this list according to a specific random source.

-    /// </summary>

-    /// <param name="rnd">The random source.</param>

-    public virtual void Shuffle(Random rnd)

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      for (int i = offset, top = offset + size, end = top - 1; i < end; i++)

-      {

-        int j = rnd.Next(i, top);

-        if (j != i)

-        {

-          T tmp = array[i];

-          array[i] = array[j];

-          array[j] = tmp;

-        }

-      }

-      disposeOverlappingViews(false);

-#if HASHINDEX

-      reindex(offset, offset + size);

-#endif

-      (underlying ?? this).raiseCollectionChanged();

-    }

-    #endregion

-

-    #region IIndexed<T> Members

-

-    /// <summary>

-    /// Search for an item in the list going forwrds from the start.

-    /// </summary>

-    /// <param name="item">Item to search for.</param>

-    /// <returns>Index of item from start.</returns>

-    [Tested]

-    public virtual int IndexOf(T item) { validitycheck(); return indexOf(item); }

-

-

-    /// <summary>

-    /// Search for an item in the list going backwords from the end.

-    /// </summary>

-    /// <param name="item">Item to search for.</param>

-    /// <returns>Index of item from the end.</returns>

-    [Tested]

-    public virtual int LastIndexOf(T item) { validitycheck(); return lastIndexOf(item); }

-

-

-    /// <summary>

-    /// Remove the item at a specific position of the list.

-    /// </summary>

-    /// <exception cref="IndexOutOfRangeException"> if index is negative or

-    /// &gt;= the size of the collection.</exception>

-    /// <param name="index">The index of the item to remove.</param>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public virtual T RemoveAt(int index)

-    {

-      updatecheck();

-      if (index < 0 || index >= size)

-        throw new IndexOutOfRangeException("Index out of range for sequenced collection");

-

-      T item = removeAt(index);

-      (underlying ?? this).raiseForRemoveAt(offset + index, item);

-      return item;

-    }

-

-

-    /// <summary>

-    /// Remove all items in an index interval.

-    /// </summary>

-    /// <exception cref="ArgumentOutOfRangeException">If <code>start</code>

-    /// and <code>count</code> does not describe a valid interval in the list</exception> 

-    /// <param name="start">The index of the first item to remove.</param>

-    /// <param name="count">The number of items to remove.</param>

-    [Tested]

-    public virtual void RemoveInterval(int start, int count)

-    {

-      updatecheck();

-      if (count == 0)

-        return;

-      checkRange(start, count);

-      start += offset;

-      fixViewsBeforeRemove(start, count);

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-      for (int i = start, end = start + count; i < end; i++)

-      {

-        p.Key = array[i];

-        itemIndex.Remove(p);

-      }

-#endif

-      Array.Copy(array, start + count, array, start, underlyingsize - start - count);

-      addtosize(-count);

-      Array.Clear(array, underlyingsize, count);

-#if HASHINDEX

-      reindex(start);

-#endif

-      (underlying ?? this).raiseForRemoveInterval(start, count);

-    }

-    void raiseForRemoveInterval(int start, int count)

-    {

-      if (ActiveEvents != 0)

-      {

-        raiseCollectionCleared(size == 0, count, start);

-        raiseCollectionChanged();

-      }

-    }

-    #endregion

-

-    #region ICollection<T> Members

-

-    /// <summary>

-    /// The value is symbolic indicating the type of asymptotic complexity

-    /// in terms of the size of this collection (worst-case or amortized as

-    /// relevant).

-    /// </summary>

-    /// <value>Speed.Linear</value>

-    [Tested]

-    public virtual Speed ContainsSpeed

-    {

-      [Tested]

-      get

-      {

-#if HASHINDEX

-        return Speed.Constant;

-#else

-        return Speed.Linear;

-#endif

-      }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    [Tested]

-    public override int GetUnsequencedHashCode()

-    { validitycheck(); return base.GetUnsequencedHashCode(); }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="that"></param>

-    /// <returns></returns>

-    [Tested]

-    public override bool UnsequencedEquals(ICollection<T> that)

-    { validitycheck(); return base.UnsequencedEquals(that); }

-

-    /// <summary>

-    /// Check if this collection contains (an item equivalent to according to the

-    /// itemequalityComparer) a particular value.

-    /// </summary>

-    /// <param name="item">The value to check for.</param>

-    /// <returns>True if the items is in this collection.</returns>

-    [Tested]

-    public virtual bool Contains(T item)

-    { validitycheck(); return indexOf(item) >= 0; }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, return in the ref argument (a

-    /// binary copy of) the actual value found.

-    /// </summary>

-    /// <param name="item">The value to look for.</param>

-    /// <returns>True if the items is in this collection.</returns>

-    [Tested]

-    public virtual bool Find(ref T item)

-    {

-      validitycheck();

-

-      int i;

-

-      if ((i = indexOf(item)) >= 0)

-      {

-        item = array[offset + i];

-        return true;

-      }

-

-      return false;

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, update the item in the collection 

-    /// to with a binary copy of the supplied value. This will only update the first 

-    /// mathching item.

-    /// </summary>

-    /// <param name="item">Value to update.</param>

-    /// <returns>True if the item was found and hence updated.</returns>

-    [Tested]

-    public virtual bool Update(T item)

-    {

-      T olditem;

-      return Update(item, out olditem);

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item"></param>

-    /// <param name="olditem"></param>

-    /// <returns></returns>

-    public virtual bool Update(T item, out T olditem)

-    {

-      updatecheck();

-      int i;

-

-      if ((i = indexOf(item)) >= 0)

-      {

-        olditem = array[offset + i];

-        array[offset + i] = item;

-#if HASHINDEX

-        itemIndex.Update(new KeyValuePair<T, int>(item, offset + i));

-#endif

-        (underlying ?? this).raiseForUpdate(item, olditem);

-        return true;

-      }

-

-      olditem = default(T);

-      return false;

-    }

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, return in the ref argument (a

-    /// binary copy of) the actual value found. Else, add the item to the collection.

-    /// </summary>

-    /// <param name="item">The value to look for.</param>

-    /// <returns>True if the item was found (hence not added).</returns>

-    [Tested]

-    public virtual bool FindOrAdd(ref T item)

-    {

-      updatecheck();

-      if (Find(ref item))

-        return true;

-

-      Add(item);

-      return false;

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, update the item in the collection 

-    /// to with a binary copy of the supplied value. This will only update the first 

-    /// mathching item.

-    /// </summary>

-    /// <param name="item">Value to update.</param>

-    /// <returns>True if the item was found and hence updated.</returns>

-    [Tested]

-    public virtual bool UpdateOrAdd(T item)

-    {

-      updatecheck();

-      if (Update(item))

-        return true;

-

-      Add(item);

-      return false;

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item"></param>

-    /// <param name="olditem"></param>

-    /// <returns></returns>

-    public virtual bool UpdateOrAdd(T item, out T olditem)

-    {

-      updatecheck();

-      if (Update(item, out olditem))

-        return true;

-

-      Add(item);

-      olditem = default(T);

-      return false;

-    }

-

-    /// <summary>

-    /// Remove a particular item from this list. The item will be searched 

-    /// for from the end of the list if <code>FIFO == false</code> (the default), 

-    /// else from the start.

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    /// <returns>True if the item was found (and removed).</returns>

-    [Tested]

-    public virtual bool Remove(T item)

-    {

-      updatecheck();

-

-      int i = fIFO ? indexOf(item) : lastIndexOf(item);

-

-      if (i < 0)

-        return false;

-

-      T removeditem = removeAt(i);

-      (underlying ?? this).raiseForRemove(removeditem);

-      return true;

-    }

-

-

-    /// <summary>

-    /// Remove the first copy of a particular item from this collection if found.

-    /// If an item was removed, report a binary copy of the actual item removed in 

-    /// the argument. The item will be searched 

-    /// for from the end of the list if <code>FIFO == false</code> (the default), 

-    /// else from the start.

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    /// <param name="removeditem">The removed value.</param>

-    /// <returns>True if the item was found (and removed).</returns>

-    [Tested]

-    public virtual bool Remove(T item, out T removeditem)

-    {

-      updatecheck();

-

-      int i = fIFO ? indexOf(item) : lastIndexOf(item);

-

-      if (i < 0)

-      {

-        removeditem = default(T);

-        return false;

-      }

-

-      removeditem = removeAt(i);

-      (underlying ?? this).raiseForRemove(removeditem);

-      return true;

-    }

-

-

-    //TODO: remove from end or according to FIFO?

-    /// <summary>

-    /// Remove all items in another collection from this one, taking multiplicities into account.

-    /// Matching items will be removed from the front. Current implementation is not optimal.

-    /// </summary>

-    /// <typeparam name="U"></typeparam>

-    /// <param name="items">The items to remove.</param>

-    [Tested]

-    public virtual void RemoveAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      //TODO: reactivate the old code for small sizes

-      HashBag<T> toremove = new HashBag<T>(itemequalityComparer);

-      toremove.AddAll(items);

-      if (toremove.Count == 0)

-        return;

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-#endif

-      while (i < end)

-      {

-        T item;

-        //pass by a stretch of nodes

-        while (i < end && !toremove.Contains(item = array[i]))

-        {

-#if HASHINDEX

-          if (j < i)

-          {

-            p.Key = item;

-            p.Value = j;

-            itemIndex.Update(p);

-          }

-#endif

-          //if (j<i)

-          array[j] = item;

-          i++; j++;

-        }

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && toremove.Remove(item = array[i]))

-        {

-#if HASHINDEX

-          p.Key = item;

-          itemIndex.Remove(p);

-#endif

-          if (mustFire)

-            raiseHandler.Remove(item);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-#if HASHINDEX

-      reindex(j);

-#endif

-      if (mustFire)

-        raiseHandler.Raise();

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="predicate"></param>

-    void RemoveAll(Fun<T, bool> predicate)

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-#endif

-      while (i < end)

-      {

-        T item;

-        //pass by a stretch of nodes

-        while (i < end && !predicate(item = array[i]))

-        {

-          updatecheck();

-#if HASHINDEX

-          if (j < i)

-          {

-            p.Key = item;

-            p.Value = j;

-            itemIndex.Update(p);

-          }

-#endif

-          //if (j<i)

-          array[j] = item;

-          i++; j++;

-        }

-        updatecheck();

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && predicate(item = array[i]))

-        {

-          updatecheck();

-#if HASHINDEX

-          p.Key = item;

-          itemIndex.Remove(p);

-#endif

-          if (mustFire)

-            raiseHandler.Remove(item);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-        updatecheck();

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-#if HASHINDEX

-      reindex(j);

-#endif

-      if (mustFire)

-        raiseHandler.Raise();

-    }

-

-    /// <summary>

-    /// Remove all items from this collection, resetting internal array size.

-    /// </summary>

-    [Tested]

-    public override void Clear()

-    {

-      if (underlying == null)

-      {

-        updatecheck();

-        if (size == 0)

-          return;

-        int oldsize = size;

-        fixViewsBeforeRemove(0, size);

-#if HASHINDEX

-        itemIndex.Clear();

-#endif

-        array = new T[8];

-        size = 0;

-        (underlying ?? this).raiseForRemoveInterval(offset, oldsize);

-      }

-      else

-        RemoveInterval(0, size);

-    }

-

-    /// <summary>

-    /// Remove all items not in some other collection from this one, taking multiplicities into account.

-    /// Items are retained front first.  

-    /// </summary>

-    /// <typeparam name="U"></typeparam>

-    /// <param name="items">The items to retain.</param>

-    [Tested]

-    public virtual void RetainAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      HashBag<T> toretain = new HashBag<T>(itemequalityComparer);

-      toretain.AddAll(items);

-      if (toretain.Count == 0)

-      {

-        Clear();

-        return;

-      }

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-#endif

-      while (i < end)

-      {

-        T item;

-        //pass by a stretch of nodes

-        while (i < end && toretain.Remove(item = array[i]))

-        {

-#if HASHINDEX

-          if (j < i)

-          {

-            p.Key = item;

-            p.Value = j;

-            itemIndex.Update(p);

-          }

-#endif

-          //if (j<i)

-          array[j] = item;

-          i++; j++;

-        }

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && !toretain.Contains(item = array[i]))

-        {

-#if HASHINDEX

-          p.Key = item;

-          itemIndex.Remove(p);

-#endif

-          if (mustFire)

-            raiseHandler.Remove(item);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-#if HASHINDEX

-      reindex(j);

-#endif

-      raiseHandler.Raise();

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="predicate"></param>

-    void RetainAll(Fun<T, bool> predicate)

-    {

-      updatecheck();

-      if (size == 0)

-        return;

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>();

-#endif

-      while (i < end)

-      {

-        T item;

-        //pass by a stretch of nodes

-        while (i < end && predicate(item = array[i]))

-        {

-          updatecheck();

-#if HASHINDEX

-          if (j < i)

-          {

-            p.Key = item;

-            p.Value = j;

-            itemIndex.Update(p);

-          }

-#endif

-          //if (j<i)

-          array[j] = item;

-          i++; j++;

-        }

-        updatecheck();

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && !predicate(item = array[i]))

-        {

-          updatecheck();

-#if HASHINDEX

-          p.Key = item;

-          itemIndex.Remove(p);

-#endif

-          if (mustFire)

-            raiseHandler.Remove(item);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-        updatecheck();

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-#if HASHINDEX

-      reindex(j);

-#endif

-      raiseHandler.Raise();

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains all the values in another collection,

-    /// taking multiplicities into account.

-    /// Current implementation is not optimal.

-    /// </summary>

-    /// <param name="items">The </param>

-    /// <typeparam name="U"></typeparam>

-    /// <returns>True if all values in <code>items</code>is in this collection.</returns>

-    [Tested]

-    public virtual bool ContainsAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      validitycheck();

-#if HASHINDEX

-      foreach (T item in items)

-        if (indexOf(item) < 0)

-          return false;

-

-      return true;

-#else

-      //TODO: use aux hash bag to obtain linear time procedure

-      HashBag<T> tomatch = new HashBag<T>(itemequalityComparer);

-      tomatch.AddAll(items);

-      if (tomatch.Count == 0)

-        return true;

-      for (int i = offset, end = offset + size; i < end; i++)

-      {

-        tomatch.Remove(array[i]);

-        if (tomatch.Count == 0)

-          return true;

-      }

-      return false;

-#endif

-    }

-

-

-    /// <summary>

-    /// Count the number of items of the collection equal to a particular value.

-    /// Returns 0 if and only if the value is not in the collection.

-    /// </summary>

-    /// <param name="item">The value to count.</param>

-    /// <returns>The number of copies found.</returns>

-    [Tested]

-    public virtual int ContainsCount(T item)

-    {

-      validitycheck();

-#if HASHINDEX

-      return indexOf(item) >= 0 ? 1 : 0;

-#else

-      int count = 0;

-      for (int i = 0; i < size; i++)

-        if (equals(item, array[offset + i]))

-          count++;

-      return count;

-#endif

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public virtual ICollectionValue<T> UniqueItems()

-    {

-#if HASHINDEX

-      return this;

-#else

-      HashBag<T> hashbag = new HashBag<T>(itemequalityComparer);

-      hashbag.AddAll(this);

-      return hashbag.UniqueItems();

-#endif

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public virtual ICollectionValue<KeyValuePair<T, int>> ItemMultiplicities()

-    {

-#if HASHINDEX

-      return new MultiplicityOne<T>(this);

-#else

-      HashBag<T> hashbag = new HashBag<T>(itemequalityComparer);

-      hashbag.AddAll(this);

-      return hashbag.ItemMultiplicities();

-#endif

-    }

-

-

-

-

-

-    /// <summary>

-    /// Remove all items equal to a given one.

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    [Tested]

-    public virtual void RemoveAllCopies(T item)

-    {

-#if HASHINDEX

-      Remove(item);

-#else

-      updatecheck();

-      if (size == 0)

-        return;

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);

-      bool mustFire = raiseHandler.MustFire;

-      ViewHandler viewHandler = new ViewHandler(this);

-      int j = offset;

-      int removed = 0;

-      int i = offset, end = offset + size;

-      while (i < end)

-      {

-        //pass by a stretch of nodes

-        while (i < end && !equals(item, array[i]))

-          array[j++] = array[i++];

-        viewHandler.skipEndpoints(removed, i);

-        //Remove a stretch of nodes

-        while (i < end && equals(item, array[i]))

-        {

-          if (mustFire)

-            raiseHandler.Remove(array[i]);

-          removed++;

-          i++;

-          viewHandler.updateViewSizesAndCounts(removed, i);

-        }

-      }

-      if (removed == 0)

-        return;

-      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);

-      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);

-      addtosize(-removed);

-      Array.Clear(array, underlyingsize, removed);

-      raiseHandler.Raise();

-#endif

-    }

-

-

-    //TODO: check views

-    /// <summary>

-    /// Check the integrity of the internal data structures of this array list.

-    /// </summary>

-    /// <returns>True if check does not fail.</returns>

-    [Tested]

-    public override bool Check()

-    {

-      bool retval = true;

-

-      if (underlyingsize > array.Length)

-      {

-        Console.WriteLine("underlyingsize ({0}) > array.Length ({1})", size, array.Length);

-        return false;

-      }

-

-      if (offset + size > underlyingsize)

-      {

-        Console.WriteLine("offset({0})+size({1}) > underlyingsize ({2})", offset, size, underlyingsize);

-        return false;

-      }

-

-      if (offset < 0)

-      {

-        Console.WriteLine("offset({0}) < 0", offset);

-        return false;

-      }

-

-      for (int i = 0; i < underlyingsize; i++)

-      {

-        if ((object)(array[i]) == null)

-        {

-          Console.WriteLine("Bad element: null at (base)index {0}", i);

-          retval = false;

-        }

-      }

-

-      for (int i = underlyingsize, length = array.Length; i < length; i++)

-      {

-        if (!equals(array[i], default(T)))

-        {

-          Console.WriteLine("Bad element: != default(T) at (base)index {0}", i);

-          retval = false;

-        }

-      }

-

-      {

-        HashedArrayList<T> u = underlying ?? this;

-        if (u.views != null)

-          foreach (HashedArrayList<T> v in u.views)

-          {

-            if (u.array != v.array)

-            {

-              Console.WriteLine("View from {0} of length has different base array than the underlying list", v.offset, v.size);

-              retval = false;

-            }

-          }

-      }

-

-

-#if HASHINDEX

-      if (underlyingsize != itemIndex.Count)

-      {

-        Console.WriteLine("size ({0})!= index.Count ({1})", size, itemIndex.Count);

-        retval = false;

-      }

-

-      for (int i = 0; i < underlyingsize; i++)

-      {

-        KeyValuePair<T, int> p = new KeyValuePair<T, int>(array[i]);

-

-        if (!itemIndex.Find(ref p))

-        {

-          Console.WriteLine("Item {1} at {0} not in hashindex", i, array[i]);

-          retval = false;

-        }

-

-        if (p.Value != i)

-        {

-          Console.WriteLine("Item {1} at {0} has hashindex {2}", i, array[i], p.Value);

-          retval = false;

-        }

-      }

-#endif

-      return retval;

-    }

-

-    #endregion

-

-    #region IExtensible<T> Members

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value>True, indicating array list has bag semantics.</value>

-    [Tested]

-    public virtual bool AllowsDuplicates

-    {

-      [Tested]

-      get

-      {

-#if HASHINDEX

-        return false;

-#else

-        return true;

-#endif

-      }

-    }

-

-    /// <summary>

-    /// By convention this is true for any collection with set semantics.

-    /// </summary>

-    /// <value>True if only one representative of a group of equal items 

-    /// is kept in the collection together with the total count.</value>

-    public virtual bool DuplicatesByCounting

-    {

-      get

-      {

-#if HASHINDEX

-        return true;

-#else

-        return false;

-#endif

-      }

-    }

-

-    /// <summary>

-    /// Add an item to end of this list.

-    /// </summary>

-    /// <param name="item">The item to add.</param>

-    /// <returns>True</returns>

-    [Tested]

-    public virtual bool Add(T item)

-    {

-      updatecheck();

-#if HASHINDEX

-      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, size + offset);

-      if (itemIndex.FindOrAdd(ref p))

-        return false;

-#endif

-      baseinsert(size, item);

-#if HASHINDEX

-      reindex(size + offset);

-#endif

-      (underlying ?? this).raiseForAdd(item);

-      return true;

-    }

-

-

-    /// <summary>

-    /// Add the elements from another collection to this collection.

-    /// </summary>

-    /// <typeparam name="U"></typeparam>

-    /// <param name="items"></param>

-    [Tested]

-    public virtual void AddAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      updatecheck();

-      int toadd = EnumerableBase<U>.countItems(items);

-      if (toadd == 0)

-        return;

-

-      if (toadd + underlyingsize > array.Length)

-        expand(toadd + underlyingsize, underlyingsize);

-

-      int i = size + offset;

-      if (underlyingsize > i)

-        Array.Copy(array, i, array, i + toadd, underlyingsize - i);

-      try

-      {

-        foreach (T item in items)

-        {

-#if HASHINDEX

-          KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, i);

-          if (itemIndex.FindOrAdd(ref p))

-            continue;

-#endif

-          array[i++] = item;

-        }

-      }

-      finally

-      {

-        int added = i - size - offset;

-        if (added < toadd)

-        {

-          Array.Copy(array, size + offset + toadd, array, i, underlyingsize - size - offset);

-          Array.Clear(array, underlyingsize + added, toadd - added);

-        }

-        if (added > 0)

-        {

-          addtosize(added);

-#if HASHINDEX

-          reindex(i);

-#endif

-          fixViewsAfterInsert(added, i - added);

-          (underlying ?? this).raiseForAddAll(i - added, added);

-        }

-      }

-    }

-    private void raiseForAddAll(int start, int added)

-    {

-      if ((ActiveEvents & EventTypeEnum.Added) != 0)

-        for (int i = start, end = start + added; i < end; i++)

-          raiseItemsAdded(array[i], 1);

-      raiseCollectionChanged();

-    }

-

-    #endregion

-

-    #region IDirectedEnumerable<T> Members

-

-    /// <summary>

-    /// Create a collection containing the same items as this collection, but

-    /// whose enumerator will enumerate the items backwards. The new collection

-    /// will become invalid if the original is modified. Method typicaly used as in

-    /// <code>foreach (T x in coll.Backwards()) {...}</code>

-    /// </summary>

-    /// <returns>The backwards collection.</returns>

-    [Tested]

-    IDirectedEnumerable<T> IDirectedEnumerable<T>.Backwards() { return Backwards(); }

-

-    #endregion

-

-    #region ICollectionValue<T> Members

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value>The number of items in this collection</value>

-    [Tested]

-    public override int Count { [Tested]get { validitycheck(); return size; } }

-    #endregion

-

-    #region IEnumerable<T> Members

-    //TODO: make tests of all calls on a disposed view throws the right exception! (Which should be C5.InvalidListViewException)

-    /// <summary>

-    /// Create an enumerator for the collection

-    /// </summary>

-    /// <returns>The enumerator</returns>

-    [Tested]

-    public override SCG.IEnumerator<T> GetEnumerator()

-    {

-      validitycheck();

-      return base.GetEnumerator();

-    }

-    #endregion

-

-#if HASHINDEX

-#else

-    #region IStack<T> Members

-

-    /// <summary>

-    /// Push an item to the top of the stack.

-    /// </summary>

-    /// <param name="item">The item</param>

-    [Tested]

-    public virtual void Push(T item)

-    {

-      InsertLast(item);

-    }

-

-    /// <summary>

-    /// Pop the item at the top of the stack from the stack.

-    /// </summary>

-    /// <returns>The popped item.</returns>

-    [Tested]

-    public virtual T Pop()

-    {

-      return RemoveLast();

-    }

-

-    #endregion

-

-    #region IQueue<T> Members

-

-    /// <summary>

-    /// Enqueue an item at the back of the queue. 

-    /// </summary>

-    /// <param name="item">The item</param>

-    [Tested]

-    public virtual void Enqueue(T item)

-    {

-      InsertLast(item);

-    }

-

-    /// <summary>

-    /// Dequeue an item from the front of the queue.

-    /// </summary>

-    /// <returns>The item</returns>

-    [Tested]

-    public virtual T Dequeue()

-    {

-      return RemoveFirst();

-    }

-

-    #endregion

-#endif

-    #region IDisposable Members

-

-    /// <summary>

-    /// Invalidate this list. If a view, just invalidate the view. 

-    /// If not a view, invalidate the list and all views on it.

-    /// </summary>

-    public virtual void Dispose()

-    {

-      Dispose(false);

-    }

-

-    void Dispose(bool disposingUnderlying)

-    {

-      if (isValid)

-      {

-        if (underlying != null)

-        {

-          isValid = false;

-          if (!disposingUnderlying && views != null)

-            views.Remove(myWeakReference);

-          underlying = null;

-          views = null;

-          myWeakReference = null;

-        }

-        else

-        {

-          //isValid = false;

-          if (views != null)

-            foreach (HashedArrayList<T> view in views)

-              view.Dispose(true);

-          Clear();

-        }

-      }

-    }

-

-    #endregion

-

-    #region ICloneable Members

-

-    /// <summary>

-    /// Make a shallow copy of this HashedArrayList.

-    /// </summary>

-    /// <returns></returns>

-    public virtual object Clone()

-    {

-      HashedArrayList<T> clone = new HashedArrayList<T>(size, itemequalityComparer);

-      clone.AddAll(this);

-      return clone;

-    }

-

-    #endregion

-

-    #region ISerializable Members

-    /*

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="info"></param>

-    /// <param name="context"></param>

-    public HashedArrayList(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) :

-      this(info.GetInt32("sz"),(SCG.IEqualityComparer<T>)(info.GetValue("eq",typeof(SCG.IEqualityComparer<T>))))

-    {

-      size = info.GetInt32("sz");

-      for (int i = 0; i < size; i++)

-      {

-        array[i] = (T)(info.GetValue("elem" + i,typeof(T)));

-      }

-#if HASHINDEX

-      reindex(0);

-#endif      

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="info"></param>

-    /// <param name="context"></param>

-    public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)

-    {

-      info.AddValue("sz", size);

-      info.AddValue("eq", EqualityComparer);

-      for (int i = 0; i < size; i++)

-			{

-        info.AddValue("elem" + i, array[i + offset]);

-      }

-    }

-*/

-    #endregion

-

-    #region System.Collections.Generic.IList<T> Members

-

-    void System.Collections.Generic.IList<T>.RemoveAt(int index)

-    {

-      RemoveAt(index);

-    }

-

-    void System.Collections.Generic.ICollection<T>.Add(T item)

-    {

-      Add(item);

-    }

-

-    #endregion

-

-    #region System.Collections.ICollection Members

-

-    bool System.Collections.ICollection.IsSynchronized

-    {

-      get { return false; }

-    }

-

-    [Obsolete]

-    Object System.Collections.ICollection.SyncRoot

-    {

-      get { return underlying != null ? ((System.Collections.ICollection)underlying).SyncRoot : array; }

-    }

-

-    void System.Collections.ICollection.CopyTo(Array arr, int index)

-    {

-      if (index < 0 || index + Count > arr.Length)

-        throw new ArgumentOutOfRangeException();

-

-      foreach (T item in this)

-        arr.SetValue(item, index++);

-    }

-

-    #endregion

-

-    #region System.Collections.IList Members

-

-    Object System.Collections.IList.this[int index]

-    {

-      get { return this[index]; }

-      set { this[index] = (T)value; }

-    }

-

-    int System.Collections.IList.Add(Object o)

-    {

-      bool added = Add((T)o);

-      // What position to report if item not added? SC.IList.Add doesn't say

-      return added ? Count - 1 : -1;

-    }

-

-    bool System.Collections.IList.Contains(Object o)

-    {

-      return Contains((T)o);

-    }

-

-    int System.Collections.IList.IndexOf(Object o)

-    {

-      return Math.Max(-1, IndexOf((T)o));

-    }

-

-    void System.Collections.IList.Insert(int index, Object o)

-    {

-      Insert(index, (T)o);

-    }

-

-    void System.Collections.IList.Remove(Object o)

-    {

-      Remove((T)o);

-    }

-

-    void System.Collections.IList.RemoveAt(int index)

-    {

-      RemoveAt(index);

-    }

-

-    #endregion

-  }

-}

+
+/*
+ Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+ 
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+ 
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+*/
+
+#define HASHINDEX
+
+using System;
+using System.Diagnostics;
+using SCG = System.Collections.Generic;
+namespace C5
+{
+  /// <summary>
+  /// A list collection based on a plain dynamic array data structure.
+  /// Expansion of the internal array is performed by doubling on demand. 
+  /// The internal array is only shrinked by the Clear method. 
+  ///
+  /// <i>When the FIFO property is set to false this class works fine as a stack of T.
+  /// When the FIFO property is set to true the class will function as a (FIFO) queue
+  /// but very inefficiently, use a LinkedList (<see cref="T:C5.LinkedList`1"/>) instead.</i>
+  /// </summary>
+  [Serializable]
+  public class HashedArrayList<T> : ArrayBase<T>, IList<T>, SCG.IList<T>
+#if HASHINDEX
+#else
+, IStack<T>, IQueue<T>
+#endif
+  {
+    #region Fields
+
+    /// <summary>
+    /// Has this list or view not been invalidated by some operation (by someone calling Dispose())
+    /// </summary>
+    bool isValid = true;
+
+    //TODO: wonder if we should save some memory on none-view situations by 
+    //      putting these three fields into a single ref field?
+    /// <summary>
+    /// The underlying list if we are a view, null else.
+    /// </summary>
+    HashedArrayList<T> underlying;
+    WeakViewList<HashedArrayList<T>> views;
+    WeakViewList<HashedArrayList<T>>.Node myWeakReference;
+
+    /// <summary>
+    /// The size of the underlying list.
+    /// </summary>
+    int underlyingsize { get { return (underlying ?? this).size; } }
+
+    /// <summary>
+    /// The underlying field of the FIFO property
+    /// </summary>
+    bool fIFO = false;
+
+#if HASHINDEX
+    HashSet<KeyValuePair<T, int>> itemIndex;
+#endif
+    #endregion
+    #region Events
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public override EventTypeEnum ListenableEvents { get { return underlying == null ? EventTypeEnum.All : EventTypeEnum.None; } }
+
+    /*
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event CollectionChangedHandler<T> CollectionChanged
+        {
+          add
+          {
+            if (underlying == null)
+              base.CollectionChanged += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.CollectionChanged -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event CollectionClearedHandler<T> CollectionCleared
+        {
+          add
+          {
+            if (underlying == null)
+              base.CollectionCleared += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.CollectionCleared -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event ItemsAddedHandler<T> ItemsAdded
+        {
+          add
+          {
+            if (underlying == null)
+              base.ItemsAdded += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.ItemsAdded -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event ItemInsertedHandler<T> ItemInserted
+        {
+          add
+          {
+            if (underlying == null)
+              base.ItemInserted += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.ItemInserted -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event ItemsRemovedHandler<T> ItemsRemoved
+        {
+          add
+          {
+            if (underlying == null)
+              base.ItemsRemoved += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.ItemsRemoved -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+        /// <summary>
+        /// 
+        /// </summary>
+        /// <value></value>
+        public override event ItemRemovedAtHandler<T> ItemRemovedAt
+        {
+          add
+          {
+            if (underlying == null)
+              base.ItemRemovedAt += value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+          remove
+          {
+            if (underlying == null)
+              base.ItemRemovedAt -= value;
+            else
+              throw new UnlistenableEventException("Can't listen to a view");
+          }
+        }
+
+          */
+
+    #endregion
+    #region Util
+
+    bool equals(T i1, T i2) { return itemequalityComparer.Equals(i1, i2); }
+
+    /// <summary>
+    /// Increment or decrement the private size fields
+    /// </summary>
+    /// <param name="delta">Increment (with sign)</param>
+    void addtosize(int delta)
+    {
+      size += delta;
+      if (underlying != null)
+        underlying.size += delta;
+    }
+
+    #region Array handling
+    /// <summary>
+    /// Double the size of the internal array.
+    /// </summary>
+    protected override void expand()
+    { expand(2 * array.Length, underlyingsize); }
+
+
+    /// <summary>
+    /// Expand the internal array, resetting the index of the first unused element.
+    /// </summary>
+    /// <param name="newcapacity">The new capacity (will be rouded upwards to a power of 2).</param>
+    /// <param name="newsize">The new count of </param>
+    protected override void expand(int newcapacity, int newsize)
+    {
+      if (underlying != null)
+        underlying.expand(newcapacity, newsize);
+      else
+      {
+        base.expand(newcapacity, newsize);
+        if (views != null)
+          foreach (HashedArrayList<T> v in views)
+            v.array = array;
+      }
+    }
+
+    #endregion
+
+    #region Checks
+    /// <summary>
+    /// Check if it is valid to perform updates and increment stamp if so.
+    /// </summary>
+    /// <exception cref="ViewDisposedException"> If check fails by this list being a disposed view.</exception>
+    /// <exception cref="ReadOnlyCollectionException"> If check fails by this being a read only list.</exception>
+    protected override void updatecheck()
+    {
+      validitycheck();
+      base.updatecheck();
+      if (underlying != null)
+        underlying.stamp++;
+    }
+
+
+    /// <summary>
+    /// Check if we are a view that the underlying list has only been updated through us.
+    /// <para>This method should be called from enumerators etc to guard against 
+    /// modification of the base collection.</para>
+    /// </summary>
+    /// <exception cref="ViewDisposedException"> if check fails.</exception>
+    void validitycheck()
+    {
+      if (!isValid)
+        throw new ViewDisposedException();
+    }
+
+
+    /// <summary>
+    /// Check that the list has not been updated since a particular time.
+    /// <para>To be used by enumerators and range </para>
+    /// </summary>
+    /// <exception cref="ViewDisposedException"> If check fails by this list being a disposed view.</exception>
+    /// <exception cref="CollectionModifiedException">If the list *has* beeen updated since that  time..</exception>
+    /// <param name="stamp">The stamp indicating the time.</param>
+    protected override void modifycheck(int stamp)
+    {
+      validitycheck();
+      if (this.stamp != stamp)
+        throw new CollectionModifiedException();
+    }
+
+    #endregion
+
+    #region Searching
+
+    /// <summary>
+    /// Internal version of IndexOf without modification checks.
+    /// </summary>
+    /// <param name="item">Item to look for</param>
+    /// <returns>The index of first occurrence</returns>
+    int indexOf(T item)
+    {
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item);
+      if (itemIndex.Find(ref p) && p.Value >= offset && p.Value < offset + size)
+        return p.Value - offset;
+#else
+      for (int i = 0; i < size; i++)
+        if (equals(item, array[offset + i]))
+          return i;
+#endif
+      return ~size;
+    }
+
+    /// <summary>
+    /// Internal version of LastIndexOf without modification checks.
+    /// </summary>
+    /// <param name="item">Item to look for</param>
+    /// <returns>The index of last occurrence</returns>
+    int lastIndexOf(T item)
+    {
+#if HASHINDEX
+      return indexOf(item);
+#else
+      for (int i = size - 1; i >= 0; i--)
+        if (equals(item, array[offset + i]))
+          return i;
+      return ~size;
+#endif
+    }
+    #endregion
+
+    #region Inserting
+
+#if HASHINDEX
+    /// <summary>
+    /// Internal version of Insert with no modification checks.
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException"> if item already in list.</exception>
+    /// <param name="i">Index to insert at</param>
+    /// <param name="item">Item to insert</param>
+#else
+    /// <summary>
+    /// Internal version of Insert with no modification checks.
+    /// </summary>
+    /// <param name="i">Index to insert at</param>
+    /// <param name="item">Item to insert</param>
+#endif
+    protected override void insert(int i, T item)
+    {
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, offset + i);
+      if (itemIndex.FindOrAdd(ref p))
+        throw new DuplicateNotAllowedException("Item already in indexed list: " + item);
+#endif
+      baseinsert(i, item);
+#if HASHINDEX
+      reindex(i + offset + 1);
+#endif
+    }
+
+    private void baseinsert(int i, T item)
+    {
+      if (underlyingsize == array.Length)
+        expand();
+      i += offset;
+      if (i < underlyingsize)
+        Array.Copy(array, i, array, i + 1, underlyingsize - i);
+      array[i] = item;
+      addtosize(1);
+      fixViewsAfterInsert(1, i);
+    }
+    #endregion
+
+    #region Removing
+
+    /// <summary>
+    /// Internal version of RemoveAt with no modification checks.
+    /// </summary>
+    /// <param name="i">Index to remove at</param>
+    /// <returns>The removed item</returns>
+    T removeAt(int i)
+    {
+      i += offset;
+      fixViewsBeforeSingleRemove(i);
+      T retval = array[i];
+      addtosize(-1);
+      if (underlyingsize > i)
+        Array.Copy(array, i + 1, array, i, underlyingsize - i);
+      array[underlyingsize] = default(T);
+#if HASHINDEX
+      itemIndex.Remove(new KeyValuePair<T, int>(retval));
+      reindex(i);
+#endif
+      return retval;
+    }
+    #endregion
+
+    #region Indexing
+
+#if HASHINDEX
+    private void reindex(int start) { reindex(start, underlyingsize); }
+
+    private void reindex(int start, int end)
+    {
+      for (int j = start; j < end; j++)
+        itemIndex.UpdateOrAdd(new KeyValuePair<T, int>(array[j], j));
+    }
+#endif
+    #endregion
+
+    #region fixView utilities
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="added">The actual number of inserted nodes</param>
+    /// <param name="realInsertionIndex"></param>
+    void fixViewsAfterInsert(int added, int realInsertionIndex)
+    {
+      if (views != null)
+        foreach (HashedArrayList<T> view in views)
+        {
+          if (view != this)
+          {
+            if (view.offset < realInsertionIndex && view.offset + view.size > realInsertionIndex)
+              view.size += added;
+            if (view.offset > realInsertionIndex || (view.offset == realInsertionIndex && view.size > 0))
+              view.offset += added;
+          }
+        }
+    }
+
+    void fixViewsBeforeSingleRemove(int realRemovalIndex)
+    {
+      if (views != null)
+        foreach (HashedArrayList<T> view in views)
+        {
+          if (view != this)
+          {
+            if (view.offset <= realRemovalIndex && view.offset + view.size > realRemovalIndex)
+              view.size--;
+            if (view.offset > realRemovalIndex)
+              view.offset--;
+          }
+        }
+    }
+
+    /// <summary>
+    /// Fix offsets and sizes of other views before removing an interval from this 
+    /// </summary>
+    /// <param name="start">the start of the interval relative to the array/underlying</param>
+    /// <param name="count"></param>
+    void fixViewsBeforeRemove(int start, int count)
+    {
+      int clearend = start + count - 1;
+      if (views != null)
+        foreach (HashedArrayList<T> view in views)
+        {
+          if (view == this)
+            continue;
+          int viewoffset = view.offset, viewend = viewoffset + view.size - 1;
+          if (start < viewoffset)
+          {
+            if (clearend < viewoffset)
+              view.offset = viewoffset - count;
+            else
+            {
+              view.offset = start;
+              view.size = clearend < viewend ? viewend - clearend : 0;
+            }
+          }
+          else if (start <= viewend)
+            view.size = clearend <= viewend ? view.size - count : start - viewoffset;
+        }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="otherOffset"></param>
+    /// <param name="otherSize"></param>
+    /// <returns>The position of View(otherOffset, otherSize) wrt. this view</returns>
+    MutualViewPosition viewPosition(int otherOffset, int otherSize)
+    {
+      int end = offset + size, otherEnd = otherOffset + otherSize;
+      if (otherOffset >= end || otherEnd <= offset)
+        return MutualViewPosition.NonOverlapping;
+      if (size == 0 || (otherOffset <= offset && end <= otherEnd))
+        return MutualViewPosition.Contains;
+      if (otherSize == 0 || (offset <= otherOffset && otherEnd <= end))
+        return MutualViewPosition.ContainedIn;
+      return MutualViewPosition.Overlapping;
+    }
+
+    //TODO: make version that fits the new, more forgiving rules for disposing
+    void disposeOverlappingViews(bool reverse)
+    {
+      if (views != null)
+        foreach (HashedArrayList<T> view in views)
+        {
+          if (view != this)
+          {
+            switch (viewPosition(view.offset, view.size))
+            {
+              case MutualViewPosition.ContainedIn:
+                if (reverse)
+                  view.offset = 2 * offset + size - view.size - view.offset;
+                else
+                  view.Dispose();
+                break;
+              case MutualViewPosition.Overlapping:
+                view.Dispose();
+                break;
+              case MutualViewPosition.Contains:
+              case MutualViewPosition.NonOverlapping:
+                break;
+            }
+          }
+        }
+    }
+    #endregion
+
+    #endregion
+
+    #region Position, PositionComparer and ViewHandler nested types
+    class PositionComparer : SCG.IComparer<Position>
+    {
+      public int Compare(Position a, Position b)
+      {
+        return a.index.CompareTo(b.index);
+      }
+    }
+    /// <summary>
+    /// During RemoveAll, we need to cache the original endpoint indices of views (??? also for HashedArrayList?)
+    /// </summary>
+    struct Position
+    {
+      public readonly HashedArrayList<T> view;
+      public readonly int index;
+      public Position(HashedArrayList<T> view, bool left)
+      {
+        this.view = view;
+        index = left ? view.offset : view.offset + view.size - 1;
+      }
+      public Position(int index) { this.index = index; view = null; }
+    }
+
+    /// <summary>
+    /// Handle the update of (other) views during a multi-remove operation.
+    /// </summary>
+    struct ViewHandler
+    {
+      HashedArrayList<Position> leftEnds;
+      HashedArrayList<Position> rightEnds;
+      int leftEndIndex, rightEndIndex;
+      internal readonly int viewCount;
+      internal ViewHandler(HashedArrayList<T> list)
+      {
+        leftEndIndex = rightEndIndex = viewCount = 0;
+        leftEnds = rightEnds = null;
+        if (list.views != null)
+          foreach (HashedArrayList<T> v in list.views)
+            if (v != list)
+            {
+              if (leftEnds == null)
+              {
+                leftEnds = new HashedArrayList<Position>();
+                rightEnds = new HashedArrayList<Position>();
+              }
+              leftEnds.Add(new Position(v, true));
+              rightEnds.Add(new Position(v, false));
+            }
+        if (leftEnds == null)
+          return;
+        viewCount = leftEnds.Count;
+        leftEnds.Sort(new PositionComparer());
+        rightEnds.Sort(new PositionComparer());
+      }
+      /// <summary>
+      /// This is to be called with realindex pointing to the first node to be removed after a (stretch of) node that was not removed
+      /// </summary>
+      /// <param name="removed"></param>
+      /// <param name="realindex"></param>
+      internal void skipEndpoints(int removed, int realindex)
+      {
+        if (viewCount > 0)
+        {
+          Position endpoint;
+          while (leftEndIndex < viewCount && (endpoint = leftEnds[leftEndIndex]).index <= realindex)
+          {
+            HashedArrayList<T> view = endpoint.view;
+            view.offset = view.offset - removed;
+            view.size += removed;
+            leftEndIndex++;
+          }
+          while (rightEndIndex < viewCount && (endpoint = rightEnds[rightEndIndex]).index < realindex)
+          {
+            endpoint.view.size -= removed;
+            rightEndIndex++;
+          }
+        }
+      }
+      internal void updateViewSizesAndCounts(int removed, int realindex)
+      {
+        if (viewCount > 0)
+        {
+          Position endpoint;
+          while (leftEndIndex < viewCount && (endpoint = leftEnds[leftEndIndex]).index <= realindex)
+          {
+            HashedArrayList<T> view = endpoint.view;
+            view.offset = view.Offset - removed;
+            view.size += removed;
+            leftEndIndex++;
+          }
+          while (rightEndIndex < viewCount && (endpoint = rightEnds[rightEndIndex]).index < realindex)
+          {
+            endpoint.view.size -= removed;
+            rightEndIndex++;
+          }
+        }
+      }
+    }
+    #endregion
+
+    #region Constructors
+    /// <summary>
+    /// Create an array list with default item equalityComparer and initial capacity 8 items.
+    /// </summary>
+    public HashedArrayList() : this(8) { }
+
+
+    /// <summary>
+    /// Create an array list with external item equalityComparer and initial capacity 8 items.
+    /// </summary>
+    /// <param name="itemequalityComparer">The external item equalityComparer</param>
+    public HashedArrayList(SCG.IEqualityComparer<T> itemequalityComparer) : this(8, itemequalityComparer) { }
+
+
+    /// <summary>
+    /// Create an array list with default item equalityComparer and prescribed initial capacity.
+    /// </summary>
+    /// <param name="capacity">The prescribed capacity</param>
+    public HashedArrayList(int capacity) : this(capacity, EqualityComparer<T>.Default) { }
+
+
+    /// <summary>
+    /// Create an array list with external item equalityComparer and prescribed initial capacity.
+    /// </summary>
+    /// <param name="capacity">The prescribed capacity</param>
+    /// <param name="itemequalityComparer">The external item equalityComparer</param>
+    public HashedArrayList(int capacity, SCG.IEqualityComparer<T> itemequalityComparer)
+      : base(capacity, itemequalityComparer)
+    {
+#if HASHINDEX
+      itemIndex = new HashSet<KeyValuePair<T, int>>(new KeyValuePairEqualityComparer<T, int>(itemequalityComparer));
+#endif
+    }
+
+    #endregion
+
+    #region IList<T> Members
+
+    /// <summary>
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <value>The first item in this list.</value>
+    [Tested]
+    public virtual T First
+    {
+      [Tested]
+      get
+      {
+        validitycheck();
+        if (size == 0)
+          throw new NoSuchItemException();
+
+        return array[offset];
+      }
+    }
+
+
+    /// <summary>
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <value>The last item in this list.</value>
+    [Tested]
+    public virtual T Last
+    {
+      [Tested]
+      get
+      {
+        validitycheck();
+        if (size == 0)
+          throw new NoSuchItemException();
+
+        return array[offset + size - 1];
+      }
+    }
+
+
+    /// <summary>
+    /// Since <code>Add(T item)</code> always add at the end of the list,
+    /// this describes if list has FIFO or LIFO semantics.
+    /// </summary>
+    /// <value>True if the <code>Remove()</code> operation removes from the
+    /// start of the list, false if it removes from the end. The default for a new array list is false.</value>
+    [Tested]
+    public virtual bool FIFO
+    {
+      [Tested]
+      get { validitycheck(); return fIFO; }
+      [Tested]
+      set { updatecheck(); fIFO = value; }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    public virtual bool IsFixedSize
+    {
+      get { validitycheck(); return false; }
+    }
+
+
+#if HASHINDEX
+    /// <summary>
+    /// On this list, this indexer is read/write.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt;= the size of the collection.</exception>
+    /// <exception cref="DuplicateNotAllowedException"> By the get operation
+    /// if the item already is present somewhere else in the list.</exception>
+    /// <value>The index'th item of this list.</value>
+    /// <param name="index">The index of the item to fetch or store.</param>
+#else
+    /// <summary>
+    /// On this list, this indexer is read/write.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt;= the size of the collection.</exception>
+    /// <value>The index'th item of this list.</value>
+    /// <param name="index">The index of the item to fetch or store.</param>
+#endif
+    [Tested]
+    public virtual T this[int index]
+    {
+      [Tested]
+      get
+      {
+        validitycheck();
+        if (index < 0 || index >= size)
+          throw new IndexOutOfRangeException();
+
+        return array[offset + index];
+      }
+      [Tested]
+      set
+      {
+        updatecheck();
+        if (index < 0 || index >= size)
+          throw new IndexOutOfRangeException();
+        index += offset;
+        T item = array[index];
+#if HASHINDEX
+        KeyValuePair<T, int> p = new KeyValuePair<T, int>(value, index);
+        if (itemequalityComparer.Equals(value, item))
+        {
+          array[index] = value;
+          itemIndex.Update(p);
+        }
+        else if (!itemIndex.FindOrAdd(ref p))
+        {
+          itemIndex.Remove(new KeyValuePair<T, int>(item));
+          array[index] = value;
+        }
+        else
+          throw new DuplicateNotAllowedException("Item already in indexed list");
+#else
+        array[index] = value;
+#endif
+        (underlying ?? this).raiseForSetThis(index, value, item);
+      }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public virtual Speed IndexingSpeed { get { return Speed.Constant; } }
+
+#if HASHINDEX
+    /// <summary>
+    /// Insert an item at a specific index location in this list. 
+    ///</summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt; the size of the collection. </exception>
+    /// <exception cref="DuplicateNotAllowedException"> 
+    /// If the item is already present in the list.</exception>
+    /// <param name="index">The index at which to insert.</param>
+    /// <param name="item">The item to insert.</param>
+#else
+    /// <summary>
+    /// Insert an item at a specific index location in this list. 
+    ///</summary>
+    /// <exception cref="IndexOutOfRangeException"> if i is negative or
+    /// &gt; the size of the collection. </exception>
+    /// <param name="index">The index at which to insert.</param>
+    /// <param name="item">The item to insert.</param>
+#endif
+    [Tested]
+    public virtual void Insert(int index, T item)
+    {
+      updatecheck();
+      if (index < 0 || index > size)
+        throw new IndexOutOfRangeException();
+
+      insert(index, item);
+      (underlying ?? this).raiseForInsert(index + offset, item);
+    }
+
+    /// <summary>
+    /// Insert an item at the end of a compatible view, used as a pointer.
+    /// <para>The <code>pointer</code> must be a view on the same list as
+    /// <code>this</code> and the endpoitn of <code>pointer</code> must be
+    /// a valid insertion point of <code>this</code></para>
+    /// </summary>
+    /// <exception cref="IncompatibleViewException">If <code>pointer</code> 
+    /// is not a view on or the same list as <code>this</code></exception>
+    /// <exception cref="IndexOutOfRangeException"><b>??????</b> if the endpoint of 
+    ///  <code>pointer</code> is not inside <code>this</code></exception>
+    /// <exception cref="DuplicateNotAllowedException"> if the list has
+    /// <code>AllowsDuplicates==false</code> and the item is 
+    /// already in the list.</exception>
+    /// <param name="pointer"></param>
+    /// <param name="item"></param>
+    public void Insert(IList<T> pointer, T item)
+    {
+      if ((pointer == null) || ((pointer.Underlying ?? pointer) != (underlying ?? this)))
+        throw new IncompatibleViewException();
+      Insert(pointer.Offset + pointer.Count - Offset, item);
+    }
+
+#if HASHINDEX
+    /// <summary>
+    /// Insert into this list all items from an enumerable collection starting 
+    /// at a particular index.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt; the size of the collection.</exception>
+    /// <exception cref="DuplicateNotAllowedException"> If <code>items</code> 
+    /// contains duplicates or some item already  present in the list.</exception>
+    /// <param name="index">Index to start inserting at</param>
+    /// <param name="items">Items to insert</param>
+#else
+    /// <summary>
+    /// Insert into this list all items from an enumerable collection starting 
+    /// at a particular index.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt; the size of the collection.</exception>
+    /// <param name="index">Index to start inserting at</param>
+    /// <param name="items">Items to insert</param>
+    /// <typeparam name="U"></typeparam>
+#endif
+    [Tested]
+    public virtual void InsertAll<U>(int index, SCG.IEnumerable<U> items) where U : T
+    {
+      updatecheck();
+      if (index < 0 || index > size)
+        throw new IndexOutOfRangeException();
+      index += offset;
+      int toadd = EnumerableBase<U>.countItems(items);
+      if (toadd == 0)
+        return;
+      if (toadd + underlyingsize > array.Length)
+        expand(toadd + underlyingsize, underlyingsize);
+      if (underlyingsize > index)
+        Array.Copy(array, index, array, index + toadd, underlyingsize - index);
+      int i = index;
+      try
+      {
+
+        foreach (T item in items)
+        {
+#if HASHINDEX
+          KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, i);
+          if (itemIndex.FindOrAdd(ref p))
+            throw new DuplicateNotAllowedException("Item already in indexed list");
+#endif
+          array[i++] = item;
+        }
+      }
+      finally
+      {
+        int added = i - index;
+        if (added < toadd)
+        {
+          Array.Copy(array, index + toadd, array, i, underlyingsize - index);
+          Array.Clear(array, underlyingsize + added, toadd - added);
+        }
+        if (added > 0)
+        {
+          addtosize(added);
+#if HASHINDEX
+          reindex(i);
+#endif
+          fixViewsAfterInsert(added, index);
+          (underlying ?? this).raiseForInsertAll(index, added);
+        }
+      }
+    }
+    private void raiseForInsertAll(int index, int added)
+    {
+      if (ActiveEvents != 0)
+      {
+        if ((ActiveEvents & (EventTypeEnum.Added | EventTypeEnum.Inserted)) != 0)
+          for (int j = index; j < index + added; j++)
+          {
+            raiseItemInserted(array[j], j);
+            raiseItemsAdded(array[j], 1);
+          }
+        raiseCollectionChanged();
+      }
+    }
+
+#if HASHINDEX
+    /// <summary>
+    /// Insert an item at the front of this list;
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException">If the item is already in the list</exception>
+    /// <param name="item">The item to insert.</param>
+#else
+    /// <summary>
+    /// Insert an item at the front of this list;
+    /// </summary>
+    /// <param name="item">The item to insert.</param>
+#endif
+    [Tested]
+    public virtual void InsertFirst(T item)
+    {
+      updatecheck();
+      insert(0, item);
+      (underlying ?? this).raiseForInsert(offset, item);
+    }
+
+
+#if HASHINDEX
+    /// <summary>
+    /// Insert an item at the back of this list.
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException">If the item is already in the list</exception>
+    /// <param name="item">The item to insert.</param>
+#else
+    /// <summary>
+    /// Insert an item at the back of this list.
+    /// </summary>
+    /// <param name="item">The item to insert.</param>
+#endif
+    [Tested]
+    public virtual void InsertLast(T item)
+    {
+      updatecheck();
+      insert(size, item);
+      (underlying ?? this).raiseForInsert(size - 1 + offset, item);
+    }
+
+
+    //NOTE: if the filter throws an exception, no result will be returned.
+    /// <summary>
+    /// Create a new list consisting of the items of this list satisfying a 
+    /// certain predicate.
+    /// <para>The new list will be of type HashedArrayList</para>
+    /// </summary>
+    /// <param name="filter">The filter delegate defining the predicate.</param>
+    /// <returns>The new list.</returns>
+    [Tested]
+    public virtual IList<T> FindAll(Fun<T, bool> filter)
+    {
+      validitycheck();
+      int stamp = this.stamp;
+      HashedArrayList<T> res = new HashedArrayList<T>(itemequalityComparer);
+      int j = 0, rescap = res.array.Length;
+      for (int i = 0; i < size; i++)
+      {
+        T a = array[offset + i];
+        bool found = filter(a);
+        modifycheck(stamp);
+        if (found)
+        {
+          if (j == rescap) res.expand(rescap = 2 * rescap, j);
+          res.array[j++] = a;
+        }
+      }
+      res.size = j;
+#if HASHINDEX
+      res.reindex(0);
+#endif
+      return res;
+    }
+
+
+#if HASHINDEX
+    /// <summary>
+    /// Create a new list consisting of the results of mapping all items of this
+    /// list. The new list will use the default item equalityComparer for the item type V.
+    /// <para>The new list will be of type HashedArrayList</para>
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException">If <code>mapper</code>
+    /// creates duplicates</exception>
+    /// <typeparam name="V">The type of items of the new list</typeparam>
+    /// <param name="mapper">The delegate defining the map.</param>
+    /// <returns>The new list.</returns>
+#else
+    /// <summary>
+    /// Create a new list consisting of the results of mapping all items of this
+    /// list. The new list will use the default item equalityComparer for the item type V.
+    /// <para>The new list will be of type HashedArrayList</para>
+    /// </summary>
+    /// <typeparam name="V">The type of items of the new list</typeparam>
+    /// <param name="mapper">The delegate defining the map.</param>
+    /// <returns>The new list.</returns>
+#endif
+    [Tested]
+    public virtual IList<V> Map<V>(Fun<T, V> mapper)
+    {
+      validitycheck();
+
+      HashedArrayList<V> res = new HashedArrayList<V>(size);
+
+      return map<V>(mapper, res);
+    }
+
+#if HASHINDEX
+    /// <summary>
+    /// Create a new list consisting of the results of mapping all items of this
+    /// list. The new list will use a specified item equalityComparer for the item type.
+    /// <para>The new list will be of type HashedArrayList</para>
+    /// </summary>
+    /// <exception cref="DuplicateNotAllowedException">If <code>mapper</code>
+    /// creates duplicates</exception>
+    /// <typeparam name="V">The type of items of the new list</typeparam>
+    /// <param name="mapper">The delegate defining the map.</param>
+    /// <param name="itemequalityComparer">The item equalityComparer to use for the new list</param>
+    /// <returns>The new list.</returns>
+#else
+    /// <summary>
+    /// Create a new list consisting of the results of mapping all items of this
+    /// list. The new list will use a specified item equalityComparer for the item type.
+    /// <para>The new list will be of type HashedArrayList</para>
+    /// </summary>
+    /// <typeparam name="V">The type of items of the new list</typeparam>
+    /// <param name="mapper">The delegate defining the map.</param>
+    /// <param name="itemequalityComparer">The item equalityComparer to use for the new list</param>
+    /// <returns>The new list.</returns>
+#endif
+    public virtual IList<V> Map<V>(Fun<T, V> mapper, SCG.IEqualityComparer<V> itemequalityComparer)
+    {
+      validitycheck();
+
+      HashedArrayList<V> res = new HashedArrayList<V>(size, itemequalityComparer);
+
+      return map<V>(mapper, res);
+    }
+
+    private IList<V> map<V>(Fun<T, V> mapper, HashedArrayList<V> res)
+    {
+      int stamp = this.stamp;
+      if (size > 0)
+        for (int i = 0; i < size; i++)
+        {
+          V mappeditem = mapper(array[offset + i]);
+          modifycheck(stamp);
+#if HASHINDEX
+          KeyValuePair<V, int> p = new KeyValuePair<V, int>(mappeditem, i);
+          if (res.itemIndex.FindOrAdd(ref p))
+            throw new ArgumentException("Mapped item already in indexed list");
+#endif
+          res.array[i] = mappeditem;
+        }
+      res.size = size;
+      return res;
+    }
+
+    /// <summary>
+    /// Remove one item from the list: from the front if <code>FIFO</code>
+    /// is true, else from the back.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public virtual T Remove()
+    {
+      updatecheck();
+      if (size == 0)
+        throw new NoSuchItemException("List is empty");
+
+      T item = removeAt(fIFO ? 0 : size - 1);
+      (underlying ?? this).raiseForRemove(item);
+      return item;
+    }
+
+    /// <summary>
+    /// Remove one item from the fromnt of the list.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public virtual T RemoveFirst()
+    {
+      updatecheck();
+      if (size == 0)
+        throw new NoSuchItemException("List is empty");
+
+      T item = removeAt(0);
+      (underlying ?? this).raiseForRemoveAt(offset, item);
+      return item;
+    }
+
+
+    /// <summary>
+    /// Remove one item from the back of the list.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if this list is empty.</exception>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public virtual T RemoveLast()
+    {
+      updatecheck();
+      if (size == 0)
+        throw new NoSuchItemException("List is empty");
+
+      T item = removeAt(size - 1);
+      (underlying ?? this).raiseForRemoveAt(size + offset, item);
+      return item;
+    }
+
+    /// <summary>
+    /// Create a list view on this list. 
+    /// </summary>
+    /// <exception cref="ArgumentOutOfRangeException"> if the start or count is negative
+    /// or the range does not fit within list.</exception>
+    /// <param name="start">The index in this list of the start of the view.</param>
+    /// <param name="count">The size of the view.</param>
+    /// <returns>The new list view.</returns>
+    [Tested]
+    public virtual IList<T> View(int start, int count)
+    {
+      validitycheck();
+      checkRange(start, count);
+      if (views == null)
+        views = new WeakViewList<HashedArrayList<T>>();
+      HashedArrayList<T> retval = (HashedArrayList<T>)MemberwiseClone();
+
+
+      retval.underlying = underlying != null ? underlying : this;
+      retval.offset = start + offset;
+      retval.size = count;
+      retval.myWeakReference = views.Add(retval);
+      return retval;
+    }
+
+    /// <summary>
+    /// Create a list view on this list containing the (first) occurrence of a particular item.
+    /// <para>Returns <code>null</code> if the item is not in this list.</para>
+    /// </summary>
+    /// <param name="item">The item to find.</param>
+    /// <returns>The new list view.</returns>
+    [Tested]
+    public virtual IList<T> ViewOf(T item)
+    {
+      int index = indexOf(item);
+      if (index < 0)
+        return null;
+      return View(index, 1);
+    }
+
+
+    /// <summary>
+    /// Create a list view on this list containing the last occurrence of a particular item. 
+    /// <para>Returns <code>null</code> if the item is not in this list.</para>
+    /// </summary>
+    /// <param name="item">The item to find.</param>
+    /// <returns>The new list view.</returns>
+    [Tested]
+    public virtual IList<T> LastViewOf(T item)
+    {
+      int index = lastIndexOf(item);
+      if (index < 0)
+        return null;
+      return View(index, 1);
+    }
+
+    /// <summary>
+    /// Null if this list is not a view.
+    /// </summary>
+    /// <value>Underlying list for view.</value>
+    [Tested]
+    public virtual IList<T> Underlying { [Tested]get { return underlying; } }
+
+
+    /// <summary>
+    /// </summary>
+    /// <value>Offset for this list view or 0 for an underlying list.</value>
+    [Tested]
+    public virtual int Offset { [Tested]get { return offset; } }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public virtual bool IsValid { get { return isValid; } }
+
+    /// <summary>
+    /// Slide this list view along the underlying list.
+    /// </summary>
+    /// <exception cref="NotAViewException"> if this list is not a view.</exception>
+    /// <exception cref="ArgumentOutOfRangeException"> if the operation
+    /// would bring either end of the view outside the underlying list.</exception>
+    /// <param name="offset">The signed amount to slide: positive to slide
+    /// towards the end.</param>
+    [Tested]
+    public virtual IList<T> Slide(int offset)
+    {
+      if (!TrySlide(offset, size))
+        throw new ArgumentOutOfRangeException();
+      return this;
+    }
+
+
+    /// <summary>
+    /// Slide this list view along the underlying list, changing its size.
+    /// </summary>
+    /// <exception cref="NotAViewException"> if this list is not a view.</exception>
+    /// <exception cref="ArgumentOutOfRangeException"> if the operation
+    /// would bring either end of the view outside the underlying list.</exception>
+    /// <param name="offset">The signed amount to slide: positive to slide
+    /// towards the end.</param>
+    /// <param name="size">The new size of the view.</param>
+    [Tested]
+    public virtual IList<T> Slide(int offset, int size)
+    {
+      if (!TrySlide(offset, size))
+        throw new ArgumentOutOfRangeException();
+      return this;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <exception cref="NotAViewException"> if this list is not a view.</exception>
+    /// <param name="offset"></param>
+    /// <returns></returns>
+    [Tested]
+    public virtual bool TrySlide(int offset)
+    {
+      return TrySlide(offset, size);
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <exception cref="NotAViewException"> if this list is not a view.</exception>
+    /// <param name="offset"></param>
+    /// <param name="size"></param>
+    /// <returns></returns>
+    [Tested]
+    public virtual bool TrySlide(int offset, int size)
+    {
+      updatecheck();
+      if (underlying == null)
+        throw new NotAViewException("Not a view");
+
+      int newoffset = this.offset + offset;
+      int newsize = size;
+
+      if (newoffset < 0 || newsize < 0 || newoffset + newsize > underlyingsize)
+        return false;
+
+      this.offset = newoffset;
+      this.size = newsize;
+      return true;
+    }
+
+    /// <summary>
+    /// 
+    /// <para>Returns null if <code>otherView</code> is strictly to the left of this view</para>
+    /// </summary>
+    /// <param name="otherView"></param>
+    /// <exception cref="IncompatibleViewException">If otherView does not have the same underlying list as this</exception>
+    /// <returns></returns>
+    public virtual IList<T> Span(IList<T> otherView)
+    {
+      if ((otherView == null) || ((otherView.Underlying ?? otherView) != (underlying ?? this)))
+        throw new IncompatibleViewException();
+      if (otherView.Offset + otherView.Count - Offset < 0)
+        return null;
+      return (underlying ?? this).View(Offset, otherView.Offset + otherView.Count - Offset);
+    }
+
+    /// <summary>
+    /// Reverst the list so the items are in the opposite sequence order.
+    /// </summary>
+    [Tested]
+    public virtual void Reverse()
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      for (int i = 0, length = size / 2, end = offset + size - 1; i < length; i++)
+      {
+        T swap = array[offset + i];
+
+        array[offset + i] = array[end - i];
+        array[end - i] = swap;
+      }
+#if HASHINDEX
+      reindex(offset, offset + size);
+#endif
+      //TODO: be more forgiving wrt. disposing
+      disposeOverlappingViews(true);
+      (underlying ?? this).raiseCollectionChanged();
+    }
+
+    /// <summary>
+    /// Check if this list is sorted according to the default sorting order
+    /// for the item type T, as defined by the <see cref="T:C5.Comparer`1"/> class 
+    /// </summary>
+    /// <exception cref="NotComparableException">if T is not comparable</exception>
+    /// <returns>True if the list is sorted, else false.</returns>
+    [Tested]
+    public bool IsSorted() { return IsSorted(Comparer<T>.Default); }
+
+    /// <summary>
+    /// Check if this list is sorted according to a specific sorting order.
+    /// </summary>
+    /// <param name="c">The comparer defining the sorting order.</param>
+    /// <returns>True if the list is sorted, else false.</returns>
+    [Tested]
+    public virtual bool IsSorted(SCG.IComparer<T> c)
+    {
+      validitycheck();
+      for (int i = offset + 1, end = offset + size; i < end; i++)
+        if (c.Compare(array[i - 1], array[i]) > 0)
+          return false;
+
+      return true;
+    }
+
+    /// <summary>
+    /// Sort the items of the list according to the default sorting order
+    /// for the item type T, as defined by the Comparer[T] class 
+    /// (<see cref="T:C5.Comparer`1"/>).
+    /// </summary>
+    /// <exception cref="InvalidOperationException">if T is not comparable</exception>
+    public virtual void Sort()
+    {
+      Sort(Comparer<T>.Default);
+    }
+
+
+    /// <summary>
+    /// Sort the items of the list according to a specific sorting order.
+    /// </summary>
+    /// <param name="comparer">The comparer defining the sorting order.</param>
+    [Tested]
+    public virtual void Sort(SCG.IComparer<T> comparer)
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      Sorting.IntroSort<T>(array, offset, size, comparer);
+      disposeOverlappingViews(false);
+#if HASHINDEX
+      reindex(offset, offset + size);
+#endif
+      (underlying ?? this).raiseCollectionChanged();
+    }
+
+
+    /// <summary>
+    /// Randomly shuffle the items of this list. 
+    /// </summary>
+    public virtual void Shuffle() { Shuffle(new C5Random()); }
+
+
+    /// <summary>
+    /// Shuffle the items of this list according to a specific random source.
+    /// </summary>
+    /// <param name="rnd">The random source.</param>
+    public virtual void Shuffle(Random rnd)
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      for (int i = offset, top = offset + size, end = top - 1; i < end; i++)
+      {
+        int j = rnd.Next(i, top);
+        if (j != i)
+        {
+          T tmp = array[i];
+          array[i] = array[j];
+          array[j] = tmp;
+        }
+      }
+      disposeOverlappingViews(false);
+#if HASHINDEX
+      reindex(offset, offset + size);
+#endif
+      (underlying ?? this).raiseCollectionChanged();
+    }
+    #endregion
+
+    #region IIndexed<T> Members
+
+    /// <summary>
+    /// Search for an item in the list going forwrds from the start.
+    /// </summary>
+    /// <param name="item">Item to search for.</param>
+    /// <returns>Index of item from start.</returns>
+    [Tested]
+    public virtual int IndexOf(T item) { validitycheck(); return indexOf(item); }
+
+
+    /// <summary>
+    /// Search for an item in the list going backwords from the end.
+    /// </summary>
+    /// <param name="item">Item to search for.</param>
+    /// <returns>Index of item from the end.</returns>
+    [Tested]
+    public virtual int LastIndexOf(T item) { validitycheck(); return lastIndexOf(item); }
+
+
+    /// <summary>
+    /// Remove the item at a specific position of the list.
+    /// </summary>
+    /// <exception cref="IndexOutOfRangeException"> if index is negative or
+    /// &gt;= the size of the collection.</exception>
+    /// <param name="index">The index of the item to remove.</param>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public virtual T RemoveAt(int index)
+    {
+      updatecheck();
+      if (index < 0 || index >= size)
+        throw new IndexOutOfRangeException("Index out of range for sequenced collection");
+
+      T item = removeAt(index);
+      (underlying ?? this).raiseForRemoveAt(offset + index, item);
+      return item;
+    }
+
+
+    /// <summary>
+    /// Remove all items in an index interval.
+    /// </summary>
+    /// <exception cref="ArgumentOutOfRangeException">If <code>start</code>
+    /// and <code>count</code> does not describe a valid interval in the list</exception> 
+    /// <param name="start">The index of the first item to remove.</param>
+    /// <param name="count">The number of items to remove.</param>
+    [Tested]
+    public virtual void RemoveInterval(int start, int count)
+    {
+      updatecheck();
+      if (count == 0)
+        return;
+      checkRange(start, count);
+      start += offset;
+      fixViewsBeforeRemove(start, count);
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+      for (int i = start, end = start + count; i < end; i++)
+      {
+        p.Key = array[i];
+        itemIndex.Remove(p);
+      }
+#endif
+      Array.Copy(array, start + count, array, start, underlyingsize - start - count);
+      addtosize(-count);
+      Array.Clear(array, underlyingsize, count);
+#if HASHINDEX
+      reindex(start);
+#endif
+      (underlying ?? this).raiseForRemoveInterval(start, count);
+    }
+    void raiseForRemoveInterval(int start, int count)
+    {
+      if (ActiveEvents != 0)
+      {
+        raiseCollectionCleared(size == 0, count, start);
+        raiseCollectionChanged();
+      }
+    }
+    #endregion
+
+    #region ICollection<T> Members
+
+    /// <summary>
+    /// The value is symbolic indicating the type of asymptotic complexity
+    /// in terms of the size of this collection (worst-case or amortized as
+    /// relevant).
+    /// </summary>
+    /// <value>Speed.Linear</value>
+    [Tested]
+    public virtual Speed ContainsSpeed
+    {
+      [Tested]
+      get
+      {
+#if HASHINDEX
+        return Speed.Constant;
+#else
+        return Speed.Linear;
+#endif
+      }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    [Tested]
+    public override int GetUnsequencedHashCode()
+    { validitycheck(); return base.GetUnsequencedHashCode(); }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="that"></param>
+    /// <returns></returns>
+    [Tested]
+    public override bool UnsequencedEquals(ICollection<T> that)
+    { validitycheck(); return base.UnsequencedEquals(that); }
+
+    /// <summary>
+    /// Check if this collection contains (an item equivalent to according to the
+    /// itemequalityComparer) a particular value.
+    /// </summary>
+    /// <param name="item">The value to check for.</param>
+    /// <returns>True if the items is in this collection.</returns>
+    [Tested]
+    public virtual bool Contains(T item)
+    { validitycheck(); return indexOf(item) >= 0; }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, return in the ref argument (a
+    /// binary copy of) the actual value found.
+    /// </summary>
+    /// <param name="item">The value to look for.</param>
+    /// <returns>True if the items is in this collection.</returns>
+    [Tested]
+    public virtual bool Find(ref T item)
+    {
+      validitycheck();
+
+      int i;
+
+      if ((i = indexOf(item)) >= 0)
+      {
+        item = array[offset + i];
+        return true;
+      }
+
+      return false;
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, update the item in the collection 
+    /// to with a binary copy of the supplied value. This will only update the first 
+    /// mathching item.
+    /// </summary>
+    /// <param name="item">Value to update.</param>
+    /// <returns>True if the item was found and hence updated.</returns>
+    [Tested]
+    public virtual bool Update(T item)
+    {
+      T olditem;
+      return Update(item, out olditem);
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item"></param>
+    /// <param name="olditem"></param>
+    /// <returns></returns>
+    public virtual bool Update(T item, out T olditem)
+    {
+      updatecheck();
+      int i;
+
+      if ((i = indexOf(item)) >= 0)
+      {
+        olditem = array[offset + i];
+        array[offset + i] = item;
+#if HASHINDEX
+        itemIndex.Update(new KeyValuePair<T, int>(item, offset + i));
+#endif
+        (underlying ?? this).raiseForUpdate(item, olditem);
+        return true;
+      }
+
+      olditem = default(T);
+      return false;
+    }
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, return in the ref argument (a
+    /// binary copy of) the actual value found. Else, add the item to the collection.
+    /// </summary>
+    /// <param name="item">The value to look for.</param>
+    /// <returns>True if the item was found (hence not added).</returns>
+    [Tested]
+    public virtual bool FindOrAdd(ref T item)
+    {
+      updatecheck();
+      if (Find(ref item))
+        return true;
+
+      Add(item);
+      return false;
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, update the item in the collection 
+    /// to with a binary copy of the supplied value. This will only update the first 
+    /// mathching item.
+    /// </summary>
+    /// <param name="item">Value to update.</param>
+    /// <returns>True if the item was found and hence updated.</returns>
+    [Tested]
+    public virtual bool UpdateOrAdd(T item)
+    {
+      updatecheck();
+      if (Update(item))
+        return true;
+
+      Add(item);
+      return false;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item"></param>
+    /// <param name="olditem"></param>
+    /// <returns></returns>
+    public virtual bool UpdateOrAdd(T item, out T olditem)
+    {
+      updatecheck();
+      if (Update(item, out olditem))
+        return true;
+
+      Add(item);
+      olditem = default(T);
+      return false;
+    }
+
+    /// <summary>
+    /// Remove a particular item from this list. The item will be searched 
+    /// for from the end of the list if <code>FIFO == false</code> (the default), 
+    /// else from the start.
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    /// <returns>True if the item was found (and removed).</returns>
+    [Tested]
+    public virtual bool Remove(T item)
+    {
+      updatecheck();
+
+      int i = fIFO ? indexOf(item) : lastIndexOf(item);
+
+      if (i < 0)
+        return false;
+
+      T removeditem = removeAt(i);
+      (underlying ?? this).raiseForRemove(removeditem);
+      return true;
+    }
+
+
+    /// <summary>
+    /// Remove the first copy of a particular item from this collection if found.
+    /// If an item was removed, report a binary copy of the actual item removed in 
+    /// the argument. The item will be searched 
+    /// for from the end of the list if <code>FIFO == false</code> (the default), 
+    /// else from the start.
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    /// <param name="removeditem">The removed value.</param>
+    /// <returns>True if the item was found (and removed).</returns>
+    [Tested]
+    public virtual bool Remove(T item, out T removeditem)
+    {
+      updatecheck();
+
+      int i = fIFO ? indexOf(item) : lastIndexOf(item);
+
+      if (i < 0)
+      {
+        removeditem = default(T);
+        return false;
+      }
+
+      removeditem = removeAt(i);
+      (underlying ?? this).raiseForRemove(removeditem);
+      return true;
+    }
+
+
+    //TODO: remove from end or according to FIFO?
+    /// <summary>
+    /// Remove all items in another collection from this one, taking multiplicities into account.
+    /// Matching items will be removed from the front. Current implementation is not optimal.
+    /// </summary>
+    /// <typeparam name="U"></typeparam>
+    /// <param name="items">The items to remove.</param>
+    [Tested]
+    public virtual void RemoveAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      //TODO: reactivate the old code for small sizes
+      HashBag<T> toremove = new HashBag<T>(itemequalityComparer);
+      toremove.AddAll(items);
+      if (toremove.Count == 0)
+        return;
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+#endif
+      while (i < end)
+      {
+        T item;
+        //pass by a stretch of nodes
+        while (i < end && !toremove.Contains(item = array[i]))
+        {
+#if HASHINDEX
+          if (j < i)
+          {
+            p.Key = item;
+            p.Value = j;
+            itemIndex.Update(p);
+          }
+#endif
+          //if (j<i)
+          array[j] = item;
+          i++; j++;
+        }
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && toremove.Remove(item = array[i]))
+        {
+#if HASHINDEX
+          p.Key = item;
+          itemIndex.Remove(p);
+#endif
+          if (mustFire)
+            raiseHandler.Remove(item);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+#if HASHINDEX
+      reindex(j);
+#endif
+      if (mustFire)
+        raiseHandler.Raise();
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="predicate"></param>
+    void RemoveAll(Fun<T, bool> predicate)
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+#endif
+      while (i < end)
+      {
+        T item;
+        //pass by a stretch of nodes
+        while (i < end && !predicate(item = array[i]))
+        {
+          updatecheck();
+#if HASHINDEX
+          if (j < i)
+          {
+            p.Key = item;
+            p.Value = j;
+            itemIndex.Update(p);
+          }
+#endif
+          //if (j<i)
+          array[j] = item;
+          i++; j++;
+        }
+        updatecheck();
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && predicate(item = array[i]))
+        {
+          updatecheck();
+#if HASHINDEX
+          p.Key = item;
+          itemIndex.Remove(p);
+#endif
+          if (mustFire)
+            raiseHandler.Remove(item);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+        updatecheck();
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+#if HASHINDEX
+      reindex(j);
+#endif
+      if (mustFire)
+        raiseHandler.Raise();
+    }
+
+    /// <summary>
+    /// Remove all items from this collection, resetting internal array size.
+    /// </summary>
+    [Tested]
+    public override void Clear()
+    {
+      if (underlying == null)
+      {
+        updatecheck();
+        if (size == 0)
+          return;
+        int oldsize = size;
+        fixViewsBeforeRemove(0, size);
+#if HASHINDEX
+        itemIndex.Clear();
+#endif
+        array = new T[8];
+        size = 0;
+        (underlying ?? this).raiseForRemoveInterval(offset, oldsize);
+      }
+      else
+        RemoveInterval(0, size);
+    }
+
+    /// <summary>
+    /// Remove all items not in some other collection from this one, taking multiplicities into account.
+    /// Items are retained front first.  
+    /// </summary>
+    /// <typeparam name="U"></typeparam>
+    /// <param name="items">The items to retain.</param>
+    [Tested]
+    public virtual void RetainAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      HashBag<T> toretain = new HashBag<T>(itemequalityComparer);
+      toretain.AddAll(items);
+      if (toretain.Count == 0)
+      {
+        Clear();
+        return;
+      }
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+#endif
+      while (i < end)
+      {
+        T item;
+        //pass by a stretch of nodes
+        while (i < end && toretain.Remove(item = array[i]))
+        {
+#if HASHINDEX
+          if (j < i)
+          {
+            p.Key = item;
+            p.Value = j;
+            itemIndex.Update(p);
+          }
+#endif
+          //if (j<i)
+          array[j] = item;
+          i++; j++;
+        }
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && !toretain.Contains(item = array[i]))
+        {
+#if HASHINDEX
+          p.Key = item;
+          itemIndex.Remove(p);
+#endif
+          if (mustFire)
+            raiseHandler.Remove(item);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+#if HASHINDEX
+      reindex(j);
+#endif
+      raiseHandler.Raise();
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="predicate"></param>
+    void RetainAll(Fun<T, bool> predicate)
+    {
+      updatecheck();
+      if (size == 0)
+        return;
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>();
+#endif
+      while (i < end)
+      {
+        T item;
+        //pass by a stretch of nodes
+        while (i < end && predicate(item = array[i]))
+        {
+          updatecheck();
+#if HASHINDEX
+          if (j < i)
+          {
+            p.Key = item;
+            p.Value = j;
+            itemIndex.Update(p);
+          }
+#endif
+          //if (j<i)
+          array[j] = item;
+          i++; j++;
+        }
+        updatecheck();
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && !predicate(item = array[i]))
+        {
+          updatecheck();
+#if HASHINDEX
+          p.Key = item;
+          itemIndex.Remove(p);
+#endif
+          if (mustFire)
+            raiseHandler.Remove(item);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+        updatecheck();
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+#if HASHINDEX
+      reindex(j);
+#endif
+      raiseHandler.Raise();
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains all the values in another collection,
+    /// taking multiplicities into account.
+    /// Current implementation is not optimal.
+    /// </summary>
+    /// <param name="items">The </param>
+    /// <typeparam name="U"></typeparam>
+    /// <returns>True if all values in <code>items</code>is in this collection.</returns>
+    [Tested]
+    public virtual bool ContainsAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      validitycheck();
+#if HASHINDEX
+      foreach (T item in items)
+        if (indexOf(item) < 0)
+          return false;
+
+      return true;
+#else
+      //TODO: use aux hash bag to obtain linear time procedure
+      HashBag<T> tomatch = new HashBag<T>(itemequalityComparer);
+      tomatch.AddAll(items);
+      if (tomatch.Count == 0)
+        return true;
+      for (int i = offset, end = offset + size; i < end; i++)
+      {
+        tomatch.Remove(array[i]);
+        if (tomatch.Count == 0)
+          return true;
+      }
+      return false;
+#endif
+    }
+
+
+    /// <summary>
+    /// Count the number of items of the collection equal to a particular value.
+    /// Returns 0 if and only if the value is not in the collection.
+    /// </summary>
+    /// <param name="item">The value to count.</param>
+    /// <returns>The number of copies found.</returns>
+    [Tested]
+    public virtual int ContainsCount(T item)
+    {
+      validitycheck();
+#if HASHINDEX
+      return indexOf(item) >= 0 ? 1 : 0;
+#else
+      int count = 0;
+      for (int i = 0; i < size; i++)
+        if (equals(item, array[offset + i]))
+          count++;
+      return count;
+#endif
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public virtual ICollectionValue<T> UniqueItems()
+    {
+#if HASHINDEX
+      return this;
+#else
+      HashBag<T> hashbag = new HashBag<T>(itemequalityComparer);
+      hashbag.AddAll(this);
+      return hashbag.UniqueItems();
+#endif
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public virtual ICollectionValue<KeyValuePair<T, int>> ItemMultiplicities()
+    {
+#if HASHINDEX
+      return new MultiplicityOne<T>(this);
+#else
+      HashBag<T> hashbag = new HashBag<T>(itemequalityComparer);
+      hashbag.AddAll(this);
+      return hashbag.ItemMultiplicities();
+#endif
+    }
+
+
+
+
+
+    /// <summary>
+    /// Remove all items equal to a given one.
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    [Tested]
+    public virtual void RemoveAllCopies(T item)
+    {
+#if HASHINDEX
+      Remove(item);
+#else
+      updatecheck();
+      if (size == 0)
+        return;
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(underlying ?? this);
+      bool mustFire = raiseHandler.MustFire;
+      ViewHandler viewHandler = new ViewHandler(this);
+      int j = offset;
+      int removed = 0;
+      int i = offset, end = offset + size;
+      while (i < end)
+      {
+        //pass by a stretch of nodes
+        while (i < end && !equals(item, array[i]))
+          array[j++] = array[i++];
+        viewHandler.skipEndpoints(removed, i);
+        //Remove a stretch of nodes
+        while (i < end && equals(item, array[i]))
+        {
+          if (mustFire)
+            raiseHandler.Remove(array[i]);
+          removed++;
+          i++;
+          viewHandler.updateViewSizesAndCounts(removed, i);
+        }
+      }
+      if (removed == 0)
+        return;
+      viewHandler.updateViewSizesAndCounts(removed, underlyingsize);
+      Array.Copy(array, offset + size, array, j, underlyingsize - offset - size);
+      addtosize(-removed);
+      Array.Clear(array, underlyingsize, removed);
+      raiseHandler.Raise();
+#endif
+    }
+
+
+    //TODO: check views
+    /// <summary>
+    /// Check the integrity of the internal data structures of this array list.
+    /// </summary>
+    /// <returns>True if check does not fail.</returns>
+    [Tested]
+    public override bool Check()
+    {
+      bool retval = true;
+
+      if (underlyingsize > array.Length)
+      {
+        Console.WriteLine("underlyingsize ({0}) > array.Length ({1})", size, array.Length);
+        return false;
+      }
+
+      if (offset + size > underlyingsize)
+      {
+        Console.WriteLine("offset({0})+size({1}) > underlyingsize ({2})", offset, size, underlyingsize);
+        return false;
+      }
+
+      if (offset < 0)
+      {
+        Console.WriteLine("offset({0}) < 0", offset);
+        return false;
+      }
+
+      for (int i = 0; i < underlyingsize; i++)
+      {
+        if ((object)(array[i]) == null)
+        {
+          Console.WriteLine("Bad element: null at (base)index {0}", i);
+          retval = false;
+        }
+      }
+
+      for (int i = underlyingsize, length = array.Length; i < length; i++)
+      {
+        if (!equals(array[i], default(T)))
+        {
+          Console.WriteLine("Bad element: != default(T) at (base)index {0}", i);
+          retval = false;
+        }
+      }
+
+      {
+        HashedArrayList<T> u = underlying ?? this;
+        if (u.views != null)
+          foreach (HashedArrayList<T> v in u.views)
+          {
+            if (u.array != v.array)
+            {
+              Console.WriteLine("View from {0} of length has different base array than the underlying list", v.offset, v.size);
+              retval = false;
+            }
+          }
+      }
+
+
+#if HASHINDEX
+      if (underlyingsize != itemIndex.Count)
+      {
+        Console.WriteLine("size ({0})!= index.Count ({1})", size, itemIndex.Count);
+        retval = false;
+      }
+
+      for (int i = 0; i < underlyingsize; i++)
+      {
+        KeyValuePair<T, int> p = new KeyValuePair<T, int>(array[i]);
+
+        if (!itemIndex.Find(ref p))
+        {
+          Console.WriteLine("Item {1} at {0} not in hashindex", i, array[i]);
+          retval = false;
+        }
+
+        if (p.Value != i)
+        {
+          Console.WriteLine("Item {1} at {0} has hashindex {2}", i, array[i], p.Value);
+          retval = false;
+        }
+      }
+#endif
+      return retval;
+    }
+
+    #endregion
+
+    #region IExtensible<T> Members
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value>True, indicating array list has bag semantics.</value>
+    [Tested]
+    public virtual bool AllowsDuplicates
+    {
+      [Tested]
+      get
+      {
+#if HASHINDEX
+        return false;
+#else
+        return true;
+#endif
+      }
+    }
+
+    /// <summary>
+    /// By convention this is true for any collection with set semantics.
+    /// </summary>
+    /// <value>True if only one representative of a group of equal items 
+    /// is kept in the collection together with the total count.</value>
+    public virtual bool DuplicatesByCounting
+    {
+      get
+      {
+#if HASHINDEX
+        return true;
+#else
+        return false;
+#endif
+      }
+    }
+
+    /// <summary>
+    /// Add an item to end of this list.
+    /// </summary>
+    /// <param name="item">The item to add.</param>
+    /// <returns>True</returns>
+    [Tested]
+    public virtual bool Add(T item)
+    {
+      updatecheck();
+#if HASHINDEX
+      KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, size + offset);
+      if (itemIndex.FindOrAdd(ref p))
+        return false;
+#endif
+      baseinsert(size, item);
+#if HASHINDEX
+      reindex(size + offset);
+#endif
+      (underlying ?? this).raiseForAdd(item);
+      return true;
+    }
+
+
+    /// <summary>
+    /// Add the elements from another collection to this collection.
+    /// </summary>
+    /// <typeparam name="U"></typeparam>
+    /// <param name="items"></param>
+    [Tested]
+    public virtual void AddAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      updatecheck();
+      int toadd = EnumerableBase<U>.countItems(items);
+      if (toadd == 0)
+        return;
+
+      if (toadd + underlyingsize > array.Length)
+        expand(toadd + underlyingsize, underlyingsize);
+
+      int i = size + offset;
+      if (underlyingsize > i)
+        Array.Copy(array, i, array, i + toadd, underlyingsize - i);
+      try
+      {
+        foreach (T item in items)
+        {
+#if HASHINDEX
+          KeyValuePair<T, int> p = new KeyValuePair<T, int>(item, i);
+          if (itemIndex.FindOrAdd(ref p))
+            continue;
+#endif
+          array[i++] = item;
+        }
+      }
+      finally
+      {
+        int added = i - size - offset;
+        if (added < toadd)
+        {
+          Array.Copy(array, size + offset + toadd, array, i, underlyingsize - size - offset);
+          Array.Clear(array, underlyingsize + added, toadd - added);
+        }
+        if (added > 0)
+        {
+          addtosize(added);
+#if HASHINDEX
+          reindex(i);
+#endif
+          fixViewsAfterInsert(added, i - added);
+          (underlying ?? this).raiseForAddAll(i - added, added);
+        }
+      }
+    }
+    private void raiseForAddAll(int start, int added)
+    {
+      if ((ActiveEvents & EventTypeEnum.Added) != 0)
+        for (int i = start, end = start + added; i < end; i++)
+          raiseItemsAdded(array[i], 1);
+      raiseCollectionChanged();
+    }
+
+    #endregion
+
+    #region IDirectedEnumerable<T> Members
+
+    /// <summary>
+    /// Create a collection containing the same items as this collection, but
+    /// whose enumerator will enumerate the items backwards. The new collection
+    /// will become invalid if the original is modified. Method typicaly used as in
+    /// <code>foreach (T x in coll.Backwards()) {...}</code>
+    /// </summary>
+    /// <returns>The backwards collection.</returns>
+    [Tested]
+    IDirectedEnumerable<T> IDirectedEnumerable<T>.Backwards() { return Backwards(); }
+
+    #endregion
+
+    #region ICollectionValue<T> Members
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value>The number of items in this collection</value>
+    [Tested]
+    public override int Count { [Tested]get { validitycheck(); return size; } }
+    #endregion
+
+    #region IEnumerable<T> Members
+    //TODO: make tests of all calls on a disposed view throws the right exception! (Which should be C5.InvalidListViewException)
+    /// <summary>
+    /// Create an enumerator for the collection
+    /// </summary>
+    /// <returns>The enumerator</returns>
+    [Tested]
+    public override SCG.IEnumerator<T> GetEnumerator()
+    {
+      validitycheck();
+      return base.GetEnumerator();
+    }
+    #endregion
+
+#if HASHINDEX
+#else
+    #region IStack<T> Members
+
+    /// <summary>
+    /// Push an item to the top of the stack.
+    /// </summary>
+    /// <param name="item">The item</param>
+    [Tested]
+    public virtual void Push(T item)
+    {
+      InsertLast(item);
+    }
+
+    /// <summary>
+    /// Pop the item at the top of the stack from the stack.
+    /// </summary>
+    /// <returns>The popped item.</returns>
+    [Tested]
+    public virtual T Pop()
+    {
+      return RemoveLast();
+    }
+
+    #endregion
+
+    #region IQueue<T> Members
+
+    /// <summary>
+    /// Enqueue an item at the back of the queue. 
+    /// </summary>
+    /// <param name="item">The item</param>
+    [Tested]
+    public virtual void Enqueue(T item)
+    {
+      InsertLast(item);
+    }
+
+    /// <summary>
+    /// Dequeue an item from the front of the queue.
+    /// </summary>
+    /// <returns>The item</returns>
+    [Tested]
+    public virtual T Dequeue()
+    {
+      return RemoveFirst();
+    }
+
+    #endregion
+#endif
+    #region IDisposable Members
+
+    /// <summary>
+    /// Invalidate this list. If a view, just invalidate the view. 
+    /// If not a view, invalidate the list and all views on it.
+    /// </summary>
+    public virtual void Dispose()
+    {
+      Dispose(false);
+    }
+
+    void Dispose(bool disposingUnderlying)
+    {
+      if (isValid)
+      {
+        if (underlying != null)
+        {
+          isValid = false;
+          if (!disposingUnderlying && views != null)
+            views.Remove(myWeakReference);
+          underlying = null;
+          views = null;
+          myWeakReference = null;
+        }
+        else
+        {
+          //isValid = false;
+          if (views != null)
+            foreach (HashedArrayList<T> view in views)
+              view.Dispose(true);
+          Clear();
+        }
+      }
+    }
+
+    #endregion
+
+    #region ICloneable Members
+
+    /// <summary>
+    /// Make a shallow copy of this HashedArrayList.
+    /// </summary>
+    /// <returns></returns>
+    public virtual object Clone()
+    {
+      HashedArrayList<T> clone = new HashedArrayList<T>(size, itemequalityComparer);
+      clone.AddAll(this);
+      return clone;
+    }
+
+    #endregion
+
+    #region ISerializable Members
+    /*
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="info"></param>
+    /// <param name="context"></param>
+    public HashedArrayList(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context) :
+      this(info.GetInt32("sz"),(SCG.IEqualityComparer<T>)(info.GetValue("eq",typeof(SCG.IEqualityComparer<T>))))
+    {
+      size = info.GetInt32("sz");
+      for (int i = 0; i < size; i++)
+      {
+        array[i] = (T)(info.GetValue("elem" + i,typeof(T)));
+      }
+#if HASHINDEX
+      reindex(0);
+#endif      
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="info"></param>
+    /// <param name="context"></param>
+    public void GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
+    {
+      info.AddValue("sz", size);
+      info.AddValue("eq", EqualityComparer);
+      for (int i = 0; i < size; i++)
+			{
+        info.AddValue("elem" + i, array[i + offset]);
+      }
+    }
+*/
+    #endregion
+
+    #region System.Collections.Generic.IList<T> Members
+
+    void System.Collections.Generic.IList<T>.RemoveAt(int index)
+    {
+      RemoveAt(index);
+    }
+
+    void System.Collections.Generic.ICollection<T>.Add(T item)
+    {
+      Add(item);
+    }
+
+    #endregion
+
+    #region System.Collections.ICollection Members
+
+    bool System.Collections.ICollection.IsSynchronized
+    {
+      get { return false; }
+    }
+
+    [Obsolete]
+    Object System.Collections.ICollection.SyncRoot
+    {
+      get { return underlying != null ? ((System.Collections.ICollection)underlying).SyncRoot : array; }
+    }
+
+    void System.Collections.ICollection.CopyTo(Array arr, int index)
+    {
+      if (index < 0 || index + Count > arr.Length)
+        throw new ArgumentOutOfRangeException();
+
+      foreach (T item in this)
+        arr.SetValue(item, index++);
+    }
+
+    #endregion
+
+    #region System.Collections.IList Members
+
+    Object System.Collections.IList.this[int index]
+    {
+      get { return this[index]; }
+      set { this[index] = (T)value; }
+    }
+
+    int System.Collections.IList.Add(Object o)
+    {
+      bool added = Add((T)o);
+      // What position to report if item not added? SC.IList.Add doesn't say
+      return added ? Count - 1 : -1;
+    }
+
+    bool System.Collections.IList.Contains(Object o)
+    {
+      return Contains((T)o);
+    }
+
+    int System.Collections.IList.IndexOf(Object o)
+    {
+      return Math.Max(-1, IndexOf((T)o));
+    }
+
+    void System.Collections.IList.Insert(int index, Object o)
+    {
+      Insert(index, (T)o);
+    }
+
+    void System.Collections.IList.Remove(Object o)
+    {
+      Remove((T)o);
+    }
+
+    void System.Collections.IList.RemoveAt(int index)
+    {
+      RemoveAt(index);
+    }
+
+    #endregion
+  }
+}
diff --git a/mcs/class/Mono.C5/C5/arrays/SortedArray.cs b/mcs/class/Mono.C5/C5/arrays/SortedArray.cs
index 5cebefa185f..931ff13de49 100644
--- a/mcs/class/Mono.C5/C5/arrays/SortedArray.cs
+++ b/mcs/class/Mono.C5/C5/arrays/SortedArray.cs
@@ -1,1476 +1,1476 @@
-/*

- Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft

- Permission is hereby granted, free of charge, to any person obtaining a copy

- of this software and associated documentation files (the "Software"), to deal

- in the Software without restriction, including without limitation the rights

- to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

- copies of the Software, and to permit persons to whom the Software is

- furnished to do so, subject to the following conditions:

- 

- The above copyright notice and this permission notice shall be included in

- all copies or substantial portions of the Software.

- 

- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

- SOFTWARE.

-*/

-

-using System;

-using System.Diagnostics;

-using SCG = System.Collections.Generic;

-namespace C5

-{

-  /// <summary>

-  /// A collection class implementing a sorted dynamic array data structure.

-  /// </summary>

-  [Serializable]

-  public class SortedArray<T> : ArrayBase<T>, IIndexedSorted<T>

-  {

-    #region Features

-    /// <summary>

-    /// A debugging artifact. To be removed.

-    /// </summary>

-    [Flags]

-    public enum Feature : short

-    {

-      /// <summary>

-      /// A debugging artifact. To be removed.

-      /// </summary>

-      Standard = 0

-    }

-

-

-    static Feature features = Feature.Standard;

-

-

-    /// <summary>

-    /// A debugging artifact. To be removed.

-    /// </summary>

-    /// <value></value>

-    public static Feature Features { get { return features; } }

-

-    #endregion

-

-    #region Events

-

-    /// <summary>

-    ///

-    /// </summary>

-    /// <value></value>

-    public override EventTypeEnum ListenableEvents { get { return EventTypeEnum.Basic; } }

-

-    #endregion

-

-    #region Fields

-

-    SCG.IComparer<T> comparer;

-

-    #endregion

-

-    #region Util

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item">The item to search for</param>

-    /// <param name="mid">The least index, mid, for which array[mid] >= item</param>

-    /// <returns>True if item found</returns>

-    private bool binarySearch(T item, out int mid)

-    {

-      int bot = 0, top = size;

-

-      mid = top / 2;

-      while (top > bot)

-      {

-        int c;

-

-        if ((c = comparer.Compare(array[mid], item)) == 0)

-          return true;

-

-        if (c > 0)

-        { top = mid; }

-        else

-        { bot = mid + 1; }

-

-        mid = (bot + top) / 2;

-      }

-

-      return false;

-    }

-

-    private int indexOf(T item)

-    {

-      int ind;

-

-      if (binarySearch(item, out ind))

-        return ind;

-

-      return ~ind;

-    }

-

-    #endregion

-

-    #region Constructors

-

-    /// <summary>

-    /// Create a dynamic sorted array with a natural comparer

-    /// (and item equalityComparer,  assumed compatible)

-    /// </summary>

-    /// <exception cref="NotComparableException">If <code>T</code> is not comparable.

-    /// </exception>

-    public SortedArray() : this(8) { }

-

-

-    /// <summary>

-    /// Create a dynamic sorted array with a natural comparer 

-    /// (and item equalityComparer,  assumed compatible)

-    /// and prescribed initial capacity.

-    /// </summary>

-    /// <exception cref="NotComparableException">If <code>T</code> is not comparable.

-    /// </exception>

-    /// <param name="capacity">The capacity</param>

-    public SortedArray(int capacity)

-      : this(capacity, Comparer<T>.Default, EqualityComparer<T>.Default) { }

-

-

-    /// <summary>

-    /// Create a dynamic sorted array with an external comparer.

-    /// <para>The itemequalityComparer will be compatible 

-    /// <see cref="T:C5.ComparerZeroHashCodeEqualityComparer`1"/> since the 

-    /// default equalityComparer for T (<see cref="P:C5.EqualityComparer`1.Default"/>)

-    /// is unlikely to be compatible with the external comparer. This makes the

-    /// array inadequate for use as item in a collection of unsequenced or sequenced sets or bags

-    /// (<see cref="T:C5.ICollection`1"/> and <see cref="T:C5.ISequenced`1"/>)

-    /// </para>

-    /// </summary>

-    /// <param name="comparer">The comparer</param>

-    public SortedArray(SCG.IComparer<T> comparer)

-      : this(8, comparer) { }

-

-    /// <summary>

-    /// Create a dynamic sorted array with an external comparer

-    /// and prescribed initial capacity.

-    /// <para>The itemequalityComparer will be a compatible 

-    /// <see cref="T:C5.ComparerZeroHashCodeEqualityComparer`1"/> since the 

-    /// default equalityComparer for T (<see cref="P:C5.EqualityComparer`1.Default"/>)

-    /// is unlikely to be compatible with the external comparer. This makes the

-    /// sorted array inadequate for use as item in a collection of unsequenced or sequenced sets or bags

-    /// (<see cref="T:C5.ICollection`1"/> and <see cref="T:C5.ISequenced`1"/>)

-    /// </para>

-    /// </summary>

-    /// <param name="capacity">The capacity</param>

-    /// <param name="comparer">The comparer</param>

-    public SortedArray(int capacity, SCG.IComparer<T> comparer)

-      : this(capacity, comparer, new ComparerZeroHashCodeEqualityComparer<T>(comparer)) { }

-

-    /// <summary>

-    /// Create a dynamic sorted array with an external comparer, an external item equalityComparer

-    /// and prescribed initial capacity. This is the constructor to use if the collection 

-    /// will be used as item in a hash table based collection.

-    /// </summary>

-    /// <param name="capacity">The capacity</param>

-    /// <param name="comparer">The item comparer</param>

-    /// <param name="equalityComparer">The item equalityComparer (assumed compatible)</param>

-    public SortedArray(int capacity, SCG.IComparer<T> comparer, SCG.IEqualityComparer<T> equalityComparer)

-      : base(capacity, equalityComparer)

-    {

-      if (comparer == null)

-        throw new NullReferenceException("Comparer cannot be null");

-      this.comparer = comparer;

-    }

-

-    #endregion

-

-    #region IIndexedSorted<T> Members

-

-    /// <summary>

-    /// Determine the number of items at or above a supplied threshold.

-    /// </summary>

-    /// <param name="bot">The lower bound (inclusive)</param>

-    /// <returns>The number of matcing items.</returns>

-    [Tested]

-    public int CountFrom(T bot)

-    {

-      int lo;

-

-      binarySearch(bot, out lo);

-      return size - lo;

-    }

-

-

-    /// <summary>

-    /// Determine the number of items between two supplied thresholds.

-    /// </summary>

-    /// <param name="bot">The lower bound (inclusive)</param>

-    /// <param name="top">The upper bound (exclusive)</param>

-    /// <returns>The number of matcing items.</returns>

-    [Tested]

-    public int CountFromTo(T bot, T top)

-    {

-      int lo, hi;

-

-      binarySearch(bot, out lo);

-      binarySearch(top, out hi);

-      return hi > lo ? hi - lo : 0;

-    }

-

-

-    /// <summary>

-    /// Determine the number of items below a supplied threshold.

-    /// </summary>

-    /// <param name="top">The upper bound (exclusive)</param>

-    /// <returns>The number of matcing items.</returns>

-    [Tested]

-    public int CountTo(T top)

-    {

-      int hi;

-

-      binarySearch(top, out hi);

-      return hi;

-    }

-

-

-    /// <summary>

-    /// Query this sorted collection for items greater than or equal to a supplied value.

-    /// </summary>

-    /// <param name="bot">The lower bound (inclusive).</param>

-    /// <returns>The result directed collection.</returns>

-    [Tested]

-    public IDirectedCollectionValue<T> RangeFrom(T bot)

-    {

-      int lo;

-

-      binarySearch(bot, out lo);

-      return new Range(this, lo, size - lo, true);

-    }

-

-

-    /// <summary>

-    /// Query this sorted collection for items between two supplied values.

-    /// </summary>

-    /// <param name="bot">The lower bound (inclusive).</param>

-    /// <param name="top">The upper bound (exclusive).</param>

-    /// <returns>The result directed collection.</returns>

-    [Tested]

-    public IDirectedCollectionValue<T> RangeFromTo(T bot, T top)

-    {

-      int lo, hi;

-

-      binarySearch(bot, out lo);

-      binarySearch(top, out hi);

-

-      int sz = hi - lo;

-

-      return new Range(this, lo, sz, true);

-    }

-

-

-    /// <summary>

-    /// Query this sorted collection for items less than a supplied value.

-    /// </summary>

-    /// <param name="top">The upper bound (exclusive).</param>

-    /// <returns>The result directed collection.</returns>

-    [Tested]

-    public IDirectedCollectionValue<T> RangeTo(T top)

-    {

-      int hi;

-

-      binarySearch(top, out hi);

-      return new Range(this, 0, hi, true);

-    }

-

-

-    /// <summary>

-    /// Create a new indexed sorted collection consisting of the items of this

-    /// indexed sorted collection satisfying a certain predicate.

-    /// </summary>

-    /// <param name="f">The filter delegate defining the predicate.</param>

-    /// <returns>The new indexed sorted collection.</returns>

-    [Tested]

-    public IIndexedSorted<T> FindAll(Fun<T, bool> f)

-    {

-      SortedArray<T> res = new SortedArray<T>(comparer);

-      int j = 0, rescap = res.array.Length;

-

-      for (int i = 0; i < size; i++)

-      {

-        T a = array[i];

-

-        if (f(a))

-        {

-          if (j == rescap) res.expand(rescap = 2 * rescap, j);

-

-          res.array[j++] = a;

-        }

-      }

-

-      res.size = j;

-      return res;

-    }

-

-

-    /// <summary>

-    /// Create a new indexed sorted collection consisting of the results of

-    /// mapping all items of this list.

-    /// <exception cref="ArgumentException"/> if the map is not increasing over 

-    /// the items of this collection (with respect to the two given comparison 

-    /// relations).

-    /// </summary>

-    /// <param name="m">The delegate definging the map.</param>

-    /// <param name="c">The comparion relation to use for the result.</param>

-    /// <returns>The new sorted collection.</returns>

-    [Tested]

-    public IIndexedSorted<V> Map<V>(Fun<T, V> m, SCG.IComparer<V> c)

-    {

-      SortedArray<V> res = new SortedArray<V>(size, c);

-

-      if (size > 0)

-      {

-        V oldv = res.array[0] = m(array[0]), newv;

-

-        for (int i = 1; i < size; i++)

-        {

-          if (c.Compare(oldv, newv = res.array[i] = m(array[i])) >= 0)

-            throw new ArgumentException("mapper not monotonic");

-

-          oldv = newv;

-        }

-      }

-

-      res.size = size;

-      return res;

-    }

-

-    #endregion

-

-    #region ISorted<T> Members

-

-    /// <summary>

-    /// Find the strict predecessor of item in the sorted array,

-    /// that is, the greatest item in the collection smaller than the item.

-    /// </summary>

-    /// <param name="item">The item to find the predecessor for.</param>

-    /// <param name="res">The predecessor, if any; otherwise the default value for T.</param>

-    /// <returns>True if item has a predecessor; otherwise false.</returns>

-    public bool TryPredecessor(T item, out T res)

-    {

-        int lo;

-        binarySearch(item, out lo);

-        if (lo == 0)

-        {

-            res = default(T);

-            return false;

-        }

-        else

-        {

-            res = array[lo - 1];

-            return true;

-        }

-    }

-

-

-    /// <summary>

-    /// Find the strict successor of item in the sorted array,

-    /// that is, the least item in the collection greater than the supplied value.

-    /// </summary>

-    /// <param name="item">The item to find the successor for.</param>

-    /// <param name="res">The successor, if any; otherwise the default value for T.</param>

-    /// <returns>True if item has a successor; otherwise false.</returns>

-    public bool TrySuccessor(T item, out T res)

-    {

-        int hi;

-        if (binarySearch(item, out hi)) 

-            hi++;

-        if (hi >= size)

-        {

-            res = default(T);

-            return false;

-        } else {

-            res = array[hi];

-            return true;

-        }

-    }

-

-

-    /// <summary>

-    /// Find the weak predecessor of item in the sorted array,

-    /// that is, the greatest item in the collection smaller than or equal to the item.

-    /// </summary>

-    /// <param name="item">The item to find the weak predecessor for.</param>

-    /// <param name="res">The weak predecessor, if any; otherwise the default value for T.</param>

-    /// <returns>True if item has a weak predecessor; otherwise false.</returns>

-    public bool TryWeakPredecessor(T item, out T res)

-    {

-        int lo;

-

-        if (!binarySearch(item, out lo)) 

-            lo--;

-

-        if (lo < 0)

-        {

-            res = default(T);

-            return false;

-        }

-        else

-        {

-            res = array[lo];

-            return true;

-        }

-    }

-

-

-    /// <summary>

-    /// Find the weak successor of item in the sorted array,

-    /// that is, the least item in the collection greater than or equal to the supplied value.

-    /// </summary>

-    /// <param name="item">The item to find the weak successor for.</param>

-    /// <param name="res">The weak successor, if any; otherwise the default value for T.</param>

-    /// <returns>True if item has a weak successor; otherwise false.</returns>

-    public bool TryWeakSuccessor(T item, out T res)

-    {

-        int hi;

-

-        binarySearch(item, out hi);

-        if (hi >= size)

-        {

-            res = default(T);

-            return false;

-        }

-        else

-        {

-            res = array[hi];

-            return true;

-        }

-    }

-

-

-    /// <summary>

-    /// Find the strict predecessor in the sorted collection of a particular value,

-    /// i.e. the largest item in the collection less than the supplied value.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if no such element exists (the

-    /// supplied  value is less than or equal to the minimum of this collection.)</exception>

-    /// <param name="item">The item to find the predecessor for.</param>

-    /// <returns>The predecessor.</returns>

-    [Tested]

-    public T Predecessor(T item)

-    {

-      int lo;

-

-      binarySearch(item, out lo);

-      if (lo == 0)

-        throw new NoSuchItemException();

-

-      return array[lo - 1];

-    }

-

-

-    /// <summary>

-    /// Find the strict successor in the sorted collection of a particular value,

-    /// i.e. the least item in the collection greater than the supplied value.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if no such element exists (the

-    /// supplied  value is greater than or equal to the maximum of this collection.)</exception>

-    /// <param name="item">The item to find the successor for.</param>

-    /// <returns>The successor.</returns>

-    [Tested]

-    public T Successor(T item)

-    {

-      int hi;

-

-      if (binarySearch(item, out hi)) hi++;

-

-      if (hi >= size)

-        throw new NoSuchItemException();

-

-      return array[hi];

-    }

-

-

-    /// <summary>

-    /// Find the weak predecessor in the sorted collection of a particular value,

-    /// i.e. the largest item in the collection less than or equal to the supplied value.

-    /// <exception cref="NoSuchItemException"/> if no such element exists (the

-    /// supplied  value is less than the minimum of this collection.)

-    /// </summary>

-    /// <param name="item">The item to find the weak predecessor for.</param>

-    /// <returns>The weak predecessor.</returns>

-    [Tested]

-    public T WeakPredecessor(T item)

-    {

-      int lo;

-

-      if (!binarySearch(item, out lo)) lo--;

-

-      if (lo < 0)

-        throw new NoSuchItemException();

-

-      return array[lo];

-    }

-

-

-    /// <summary>

-    /// Find the weak successor in the sorted collection of a particular value,

-    /// i.e. the least item in the collection greater than or equal to the supplied value.

-    /// </summary>

-    /// <exception cref="NoSuchItemException"> if no such element exists (the

-    /// supplied  value is greater than the maximum of this collection.)</exception>

-    /// <param name="item">The item to find the weak successor for.</param>

-    /// <returns>The weak successor.</returns>

-    [Tested]

-    public T WeakSuccessor(T item)

-    {

-      int hi;

-

-      binarySearch(item, out hi);

-      if (hi >= size)

-        throw new NoSuchItemException();

-

-      return array[hi];

-    }

-

-

-    /// <summary>

-    /// Perform a search in the sorted collection for the ranges in which a

-    /// non-increasing (i.e. weakly decrerasing) function from the item type to 

-    /// <code>int</code> is

-    /// negative, zero respectively positive. If the supplied cut function is

-    /// not non-increasing, the result of this call is undefined.

-    /// </summary>

-    /// <param name="c">The cut function <code>T</code> to <code>int</code>, given

-    /// as an <code>IComparable&lt;T&gt;</code> object, where the cut function is

-    /// the <code>c.CompareTo(T that)</code> method.</param>

-    /// <param name="low">Returns the largest item in the collection, where the

-    /// cut function is positive (if any).</param>

-    /// <param name="lowIsValid">True if the cut function is positive somewhere

-    /// on this collection.</param>

-    /// <param name="high">Returns the least item in the collection, where the

-    /// cut function is negative (if any).</param>

-    /// <param name="highIsValid">True if the cut function is negative somewhere

-    /// on this collection.</param>

-    /// <returns></returns>

-    [Tested]

-    public bool Cut(IComparable<T> c, out T low, out bool lowIsValid, out T high, out bool highIsValid)

-    {

-      int lbest = -1, rbest = size;

-

-      low = default(T);

-      lowIsValid = false;

-      high = default(T);

-      highIsValid = false;

-

-      int bot = 0, top = size, mid, comp = -1, sol;

-

-      mid = top / 2;

-      while (top > bot)

-      {

-        if ((comp = c.CompareTo(array[mid])) == 0)

-          break;

-

-        if (comp < 0)

-        { rbest = top = mid; }

-        else

-        { lbest = mid; bot = mid + 1; }

-

-        mid = (bot + top) / 2;

-      }

-

-      if (comp != 0)

-      {

-        if (lbest >= 0) { lowIsValid = true; low = array[lbest]; }

-

-        if (rbest < size) { highIsValid = true; high = array[rbest]; }

-

-        return false;

-      }

-

-      sol = mid;

-      bot = sol - 1;

-

-      //Invariant: c.Compare(array[x]) < 0  when rbest <= x < size 

-      //           c.Compare(array[x]) >= 0 when x < bot)

-      //(Assuming c.Compare monotonic)

-      while (rbest > bot)

-      {

-        mid = (bot + rbest) / 2;

-        if (c.CompareTo(array[mid]) < 0)

-        { rbest = mid; }

-        else

-        { bot = mid + 1; }

-      }

-

-      if (rbest < size) { highIsValid = true; high = array[rbest]; }

-

-      top = sol + 1;

-

-      //Invariant: c.Compare(array[x]) > 0  when 0 <= x <= lbest

-      //           c.Compare(array[x]) <= 0 when x>top)

-      //(Assuming c.Compare monotonic)

-      while (top > lbest)

-      {

-        mid = (lbest + top + 1) / 2;

-        if (c.CompareTo(array[mid]) > 0)

-        { lbest = mid; }

-        else

-        { top = mid - 1; }

-      }

-

-      if (lbest >= 0) { lowIsValid = true; low = array[lbest]; }

-

-      return true;

-    }

-

-

-    IDirectedEnumerable<T> ISorted<T>.RangeFrom(T bot)

-    { return RangeFrom(bot); }

-

-

-    IDirectedEnumerable<T> ISorted<T>.RangeFromTo(T bot, T top)

-    { return RangeFromTo(bot, top); }

-

-

-    IDirectedEnumerable<T> ISorted<T>.RangeTo(T top)

-    { return RangeTo(top); }

-

-

-    /// <summary>

-    /// Create a directed collection with the same items as this collection.

-    /// </summary>

-    /// <returns>The result directed collection.</returns>

-    [Tested]

-    public IDirectedCollectionValue<T> RangeAll()

-    { return new Range(this, 0, size, true); }

-

-

-    /// <summary>

-    /// Add all the items from another collection with an enumeration order that 

-    /// is increasing in the items.

-    /// <exception cref="ArgumentException"/> if the enumerated items turns out

-    /// not to be in increasing order.

-    /// </summary>

-    /// <param name="items">The collection to add.</param>

-    /// <typeparam name="U"></typeparam>

-    [Tested]

-    public void AddSorted<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      //Unless items have <=1 elements we would expect it to be

-      //too expensive to do repeated inserts, thus:

-      updatecheck();

-

-      int j = 0, i = 0, c = -1, itemcount = EnumerableBase<U>.countItems(items), numAdded = 0;

-      SortedArray<T> res = new SortedArray<T>(size + itemcount, comparer);

-      T lastitem = default(T);

-      T[] addedItems = new T[itemcount];

-

-      foreach (T item in items)

-      {

-        while (i < size && (c = comparer.Compare(array[i], item)) <= 0)

-        {

-          lastitem = res.array[j++] = array[i++];

-          if (c == 0)

-            goto next;

-        }

-

-        if (j > 0 && comparer.Compare(lastitem, item) >= 0)

-          throw new ArgumentException("Argument not sorted");

-

-        addedItems[numAdded++] = lastitem = res.array[j++] = item;

-      next:

-        c = -1;

-      }

-

-      while (i < size) res.array[j++] = array[i++];

-

-      size = j;

-      array = res.array;

-      raiseForAddAll(addedItems, numAdded);

-    }

-

-

-    /// <summary>

-    /// Remove all items of this collection above or at a supplied threshold.

-    /// </summary>

-    /// <param name="low">The lower threshold (inclusive).</param>

-    [Tested]

-    public void RemoveRangeFrom(T low)

-    {

-      int lowind;

-

-      binarySearch(low, out lowind);

-      if (lowind == size)

-        return;

-

-      T[] removed = new T[size - lowind];

-      Array.Copy(array, lowind, removed, 0, removed.Length);

-      Array.Reverse(removed);

-

-      Array.Clear(array, lowind, size - lowind);

-      size = lowind;

-

-      raiseForRemoveRange(removed);

-    }

-

-

-    /// <summary>

-    /// Remove all items of this collection between two supplied thresholds.

-    /// </summary>

-    /// <param name="low">The lower threshold (inclusive).</param>

-    /// <param name="hi">The upper threshold (exclusive).</param>

-    [Tested]

-    public void RemoveRangeFromTo(T low, T hi)

-    {

-      int lowind, highind;

-

-      binarySearch(low, out lowind);

-      binarySearch(hi, out highind);

-      if (highind <= lowind)

-        return;

-

-      T[] removed = new T[highind - lowind];

-      Array.Copy(array, lowind, removed, 0, removed.Length);

-      Array.Reverse(removed);

-

-      Array.Copy(array, highind, array, lowind, size - highind);

-      Array.Clear(array, size - highind + lowind, highind - lowind);

-      size -= highind - lowind;

-

-      raiseForRemoveRange(removed);

-    }

-

-

-    /// <summary>

-    /// Remove all items of this collection below a supplied threshold.

-    /// </summary>

-    /// <param name="hi">The upper threshold (exclusive).</param>

-    [Tested]

-    public void RemoveRangeTo(T hi)

-    {

-      int highind;

-

-      binarySearch(hi, out highind);

-      if (highind == 0)

-        return;

-

-      T[] removed = new T[highind];

-      Array.Copy(array, 0, removed, 0, removed.Length);

-

-      Array.Copy(array, highind, array, 0, size - highind);

-      Array.Clear(array, size - highind, highind);

-      size = size - highind;

-

-      raiseForRemoveRange(removed);

-    }

-

-    private void raiseForRemoveRange(T[] removed)

-    {

-       foreach(T item in removed)

-         raiseItemsRemoved(item, 1);

-

-       if(removed.Length > 0)

-         raiseCollectionChanged();

-    }

-

-    #endregion

-

-    #region ICollection<T> Members

-    /// <summary>

-    /// The value is symbolic indicating the type of asymptotic complexity

-    /// in terms of the size of this collection (worst-case).

-    /// </summary>

-    /// <value>Speed.Log</value>

-    [Tested]

-    public Speed ContainsSpeed { [Tested]get { return Speed.Log; } }

-

-    /// <summary>

-    /// Remove all items from this collection, resetting internal array size.

-    /// </summary>

-    [Tested]

-    override public void Clear()

-    {

-      int oldCount = size;

-      base.Clear();

-      if(oldCount > 0)

-      {

-        raiseCollectionCleared(true, oldCount);

-        raiseCollectionChanged();

-      }

-    }

-

-    /// <summary>

-    /// Check if this collection contains (an item equivalent according to the

-    /// itemequalityComparer) to a particular value.

-    /// </summary>

-    /// <param name="item">The value to check for.</param>

-    /// <returns>True if the items is in this collection.</returns>

-    [Tested]

-    public bool Contains(T item)

-    {

-      int ind;

-

-      return binarySearch(item, out ind);

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, return in the ref argument (a

-    /// binary copy of) the actual value found.

-    /// </summary>

-    /// <param name="item">The value to look for.</param>

-    /// <returns>True if the items is in this collection.</returns>

-    [Tested]

-    public bool Find(ref T item)

-    {

-      int ind;

-

-      if (binarySearch(item, out ind))

-      {

-        item = array[ind];

-        return true;

-      }

-

-      return false;

-    }

-

-

-    //This should probably just be bool Add(ref T item); !!!

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, return in the ref argument (a

-    /// binary copy of) the actual value found. Else, add the item to the collection.

-    /// </summary>

-    /// <param name="item">The value to look for.</param>

-    /// <returns>True if the item was added (hence not found).</returns>

-    [Tested]

-    public bool FindOrAdd(ref T item)

-    {

-      updatecheck();

-

-      int ind;

-

-      if (binarySearch(item, out ind))

-      {

-        item = array[ind];

-        return true;

-      }

-

-      if (size == array.Length) expand();

-

-      Array.Copy(array, ind, array, ind + 1, size - ind);

-      array[ind] = item;

-      size++;

-      raiseForAdd(item);

-      return false;

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, update the item in the collection 

-    /// to with a binary copy of the supplied value. If the collection has bag semantics,

-    /// it is implementation dependent if this updates all equivalent copies in

-    /// the collection or just one.

-    /// </summary>

-    /// <param name="item">Value to update.</param>

-    /// <returns>True if the item was found and hence updated.</returns>

-    [Tested]

-    public bool Update(T item)

-    { T olditem; return Update(item, out olditem); }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item"></param>

-    /// <param name="olditem"></param>

-    /// <returns></returns>

-    public bool Update(T item, out T olditem)

-    {

-      updatecheck();

-

-      int ind;

-

-      if (binarySearch(item, out ind))

-      {

-        olditem = array[ind];

-        array[ind] = item;

-        raiseForUpdate(item, olditem);

-        return true;

-      }

-

-      olditem = default(T);

-      return false;

-    }

-

-

-    /// <summary>

-    /// Check if this collection contains an item equivalent according to the

-    /// itemequalityComparer to a particular value. If so, update the item in the collection 

-    /// to with a binary copy of the supplied value; else add the value to the collection. 

-    /// </summary>

-    /// <param name="item">Value to add or update.</param>

-    /// <returns>True if the item was found and updated (hence not added).</returns>

-    [Tested]

-    public bool UpdateOrAdd(T item)

-    { T olditem; return UpdateOrAdd(item, out olditem); }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <param name="item"></param>

-    /// <param name="olditem"></param>

-    /// <returns></returns>

-    public bool UpdateOrAdd(T item, out T olditem)

-    {

-      updatecheck();

-

-      int ind;

-

-      if (binarySearch(item, out ind))

-      {

-        olditem = array[ind];

-        array[ind] = item;

-        raiseForUpdate(item, olditem);

-        return true;

-      }

-

-      if (size == array.Length) expand();

-

-      Array.Copy(array, ind, array, ind + 1, size - ind);

-      array[ind] = item;

-      size++;

-      olditem = default(T);

-      raiseForAdd(item);

-      return false;

-    }

-

-

-    /// <summary>

-    /// Remove a particular item from this collection. If the collection has bag

-    /// semantics only one copy equivalent to the supplied item is removed. 

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    /// <returns>True if the item was found (and removed).</returns>

-    [Tested]

-    public bool Remove(T item)

-    {

-      int ind;

-

-      updatecheck();

-      if (binarySearch(item, out ind))

-      {

-        T removeditem = array[ind];

-        Array.Copy(array, ind + 1, array, ind, size - ind - 1);

-        array[--size] = default(T);

-        raiseForRemove(removeditem);

-        return true;

-      }

-

-      return false;

-    }

-

-

-    /// <summary>

-    /// Remove a particular item from this collection if found. If the collection

-    /// has bag semantics only one copy equivalent to the supplied item is removed,

-    /// which one is implementation dependent. 

-    /// If an item was removed, report a binary copy of the actual item removed in 

-    /// the argument.

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    /// <param name="removeditem">The removed value.</param>

-    /// <returns>True if the item was found (and removed).</returns>

-    [Tested]

-    public bool Remove(T item, out T removeditem)

-    {

-      int ind;

-

-      updatecheck();

-      if (binarySearch(item, out ind))

-      {

-        removeditem = array[ind];

-        Array.Copy(array, ind + 1, array, ind, size - ind - 1);

-        array[--size] = default(T);

-        raiseForRemove(removeditem);

-        return true;

-      }

-

-      removeditem = default(T);

-      return false;

-    }

-

-

-    /// <summary>

-    /// Remove all items in another collection from this one. 

-    /// </summary>

-    /// <typeparam name="U"></typeparam>

-    /// <param name="items">The items to remove.</param>

-    [Tested]

-    public void RemoveAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      //This is O(m*logn) with n bits extra storage

-      //(Not better to collect the m items and sort them)

-      updatecheck();

-        

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(this);

-      bool mustFire = raiseHandler.MustFire;

-

-      int[] toremove = new int[(size >> 5) + 1];

-      int ind, j = 0;

-

-      foreach (T item in items)

-        if (binarySearch(item, out ind))

-          toremove[ind >> 5] |= 1 << (ind & 31);

-

-      for (int i = 0; i < size; i++)

-        if ((toremove[i >> 5] & (1 << (i & 31))) == 0)

-          array[j++] = array[i];

-        else if (mustFire)

-          raiseHandler.Remove(array[i]);

-

-      Array.Clear(array, j, size - j);

-      size = j;

-      if (mustFire)

-        raiseHandler.Raise();

-    }

-

-    /// <summary>

-    /// Remove all items not in some other collection from this one. 

-    /// </summary>

-    /// <typeparam name="U"></typeparam>

-    /// <param name="items">The items to retain.</param>

-    [Tested]

-    public void RetainAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      //This is O(m*logn) with n bits extra storage

-      //(Not better to collect the m items and sort them)

-      updatecheck();

-

-      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(this);

-      bool mustFire = raiseHandler.MustFire;

-

-      int[] toretain = new int[(size >> 5) + 1];

-      int ind, j = 0;

-

-      foreach (T item in items)

-        if (binarySearch(item, out ind))

-          toretain[ind >> 5] |= 1 << (ind & 31);

-

-      for (int i = 0; i < size; i++)

-        if ((toretain[i >> 5] & (1 << (i & 31))) != 0)

-          array[j++] = array[i];

-        else if (mustFire)

-          raiseHandler.Remove(array[i]);

-

-      Array.Clear(array, j, size - j);

-      size = j;

-      if (mustFire)

-        raiseHandler.Raise();

-    }

-

-    /// <summary>

-    /// Check if this collection contains all the values in another collection.

-    /// Multiplicities are not taken into account.

-    /// </summary>

-    /// <param name="items">The </param>

-    /// <typeparam name="U"></typeparam>

-    /// <returns>True if all values in <code>items</code>is in this collection.</returns>

-    [Tested]

-    public bool ContainsAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      int tmp;

-

-      foreach (T item in items)

-        if (!binarySearch(item, out tmp))

-          return false;

-

-      return true;

-    }

-

-

-    /// <summary>

-    /// Count the number of items of the collection equal to a particular value.

-    /// Returns 0 if and only if the value is not in the collection.

-    /// </summary>

-    /// <param name="item">The value to count.</param>

-    /// <returns>The number of copies found (0 or 1).</returns>

-    [Tested]

-    public int ContainsCount(T item)

-    {

-      int tmp;

-

-      return binarySearch(item, out tmp) ? 1 : 0;

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public virtual ICollectionValue<T> UniqueItems() { return this; }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <returns></returns>

-    public virtual ICollectionValue<KeyValuePair<T, int>> ItemMultiplicities()

-    {

-      return new MultiplicityOne<T>(this);

-    }

-

-    /// <summary>

-    /// Remove all (0 or 1) items equivalent to a given value.

-    /// </summary>

-    /// <param name="item">The value to remove.</param>

-    [Tested]

-    public void RemoveAllCopies(T item) { Remove(item); }

-

-

-    /// <summary>

-    /// Check the integrity of the internal data structures of this collection.

-    /// Only avaliable in DEBUG builds???

-    /// </summary>

-    /// <returns>True if check does not fail.</returns>

-    [Tested]

-    public override bool Check()

-    {

-      bool retval = true;

-

-      if (size > array.Length)

-      {

-        Console.WriteLine("Bad size ({0}) > array.Length ({1})", size, array.Length);

-        return false;

-      }

-

-      for (int i = 0; i < size; i++)

-      {

-        if ((object)(array[i]) == null)

-        {

-          Console.WriteLine("Bad element: null at index {0}", i);

-          return false;

-        }

-

-        if (i > 0 && comparer.Compare(array[i], array[i - 1]) <= 0)

-        {

-          Console.WriteLine("Inversion at index {0}", i);

-          retval = false;

-        }

-      }

-

-      return retval;

-    }

-

-    #endregion

-

-    #region IExtensible<T> Members

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value>False since this collection has set semantics</value>

-    [Tested]

-    public bool AllowsDuplicates { [Tested]get { return false; } }

-

-    /// <summary>

-    /// By convention this is true for any collection with set semantics.

-    /// </summary>

-    /// <value>True if only one representative of a group of equal items 

-    /// is kept in the collection together with the total count.</value>

-    public virtual bool DuplicatesByCounting { get { return true; } }

-

-    /// <summary>

-    /// Add an item to this collection if possible. If this collection has set

-    /// semantics, the item will be added if not already in the collection. If

-    /// bag semantics, the item will always be added.

-    /// </summary>

-    /// <param name="item">The item to add.</param>

-    /// <returns>True if item was added.</returns>

-    [Tested]

-    public bool Add(T item)

-    {

-      updatecheck();

-

-      int ind;

-

-      if (binarySearch(item, out ind)) return false;

-

-      insert(ind, item);

-      raiseForAdd(item);

-      return true;

-    }

-

-    /// <summary>

-    /// Add an item to this collection if possible. 

-    /// </summary>

-    /// <param name="item">The item to add.</param>

-    [Tested]

-    void SCG.ICollection<T>.Add(T item)

-    {

-        Add(item);

-    }

-

-

-    /// <summary>

-    /// Add the elements from another collection with a more specialized item type 

-    /// to this collection. Since this

-    /// collection has set semantics, only items not already in the collection

-    /// will be added.

-    /// </summary>

-    /// <typeparam name="U">The type of items to add</typeparam>

-    /// <param name="items">The items to add</param>

-    [Tested]

-    public void AddAll<U>(SCG.IEnumerable<U> items) where U : T

-    {

-      int toadd = EnumerableBase<U>.countItems(items), newsize = array.Length;

-

-      while (newsize < size + toadd) { newsize *= 2; }

-

-      T[] newarr = new T[newsize];

-

-      toadd = 0;

-      foreach (T item in items) newarr[size + toadd++] = item;

-

-      Sorting.IntroSort<T>(newarr, size, toadd, comparer);

-

-      int j = 0, i = 0, numAdded = 0;

-      T lastitem = default(T);

-      T[] addedItems = new T[toadd];

-

-      //The following eliminates duplicates (including duplicates in input)

-      //while merging the old and new collection

-      for (int k = size, klimit = size + toadd; k < klimit; k++)

-      {

-        while (i < size && comparer.Compare(array[i], newarr[k]) <= 0)

-          lastitem = newarr[j++] = array[i++];

-

-        if (j == 0 || comparer.Compare(lastitem, newarr[k]) < 0)

-          addedItems[numAdded++] = lastitem = newarr[j++] = newarr[k];

-      }

-

-      while (i < size) newarr[j++] = array[i++];

-

-      Array.Clear(newarr, j, size + toadd - j);

-      size = j;

-      array = newarr;

-

-      raiseForAddAll(addedItems, numAdded);

-    }

-

-    private void raiseForAddAll(T[] addedItems, int numAdded)

-    {

-      if ((ActiveEvents & EventTypeEnum.Added) != 0)

-        for(int i = 0 ;i < numAdded; i += 1)

-          raiseItemsAdded(addedItems[i], 1);

-      if (numAdded > 0)

-        raiseCollectionChanged();

-    }

-

-    #endregion

-

-    #region IPriorityQueue<T> Members

-

-    /// <summary>

-    /// Find the current least item of this priority queue.

-    /// </summary>

-    /// <returns>The least item.</returns>

-    [Tested]

-    public T FindMin()

-    {

-      if (size == 0)

-        throw new NoSuchItemException();

-

-      return array[0];

-    }

-

-    /// <summary>

-    /// Remove the least item from this  priority queue.

-    /// </summary>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public T DeleteMin()

-    {

-      updatecheck();

-      if (size == 0)

-        throw new NoSuchItemException();

-

-      T retval = array[0];

-

-      size--;

-      Array.Copy(array, 1, array, 0, size);

-      array[size] = default(T);

-      raiseForRemove(retval);

-      return retval;

-    }

-

-

-    /// <summary>

-    /// Find the current largest item of this priority queue.

-    /// </summary>

-    /// <returns>The largest item.</returns>

-    [Tested]

-    public T FindMax()

-    {

-      if (size == 0)

-        throw new NoSuchItemException();

-

-      return array[size - 1];

-    }

-

-

-    /// <summary>

-    /// Remove the largest item from this  priority queue.

-    /// </summary>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public T DeleteMax()

-    {

-      updatecheck();

-      if (size == 0)

-        throw new NoSuchItemException();

-

-      T retval = array[size - 1];

-

-      size--;

-      array[size] = default(T);

-      raiseForRemove(retval);

-      return retval;

-    }

-

-    /// <summary>

-    /// The comparer object supplied at creation time for this collection

-    /// </summary>

-    /// <value>The comparer</value>

-    public SCG.IComparer<T> Comparer { get { return comparer; } }

-

-    #endregion

-

-    #region IIndexed<T> Members

-

-    /// <summary>

-    /// <exception cref="IndexOutOfRangeException"/> if i is negative or

-    /// &gt;= the size of the collection.

-    /// </summary>

-    /// <value>The i'th item of this list.</value>

-    /// <param name="i">the index to lookup</param>

-    [Tested]

-    public T this[int i]

-    {

-      [Tested]

-      get

-      {

-        if (i < 0 || i >= size)

-          throw new IndexOutOfRangeException();

-

-        return array[i];

-      }

-    }

-

-    /// <summary>

-    /// 

-    /// </summary>

-    /// <value></value>

-    public virtual Speed IndexingSpeed { get { return Speed.Constant; } }

-

-    /// <summary>

-    /// Searches for an item in the list going forwrds from the start.

-    /// </summary>

-    /// <param name="item">Item to search for.</param>

-    /// <returns>Index of item from start.</returns>

-    [Tested]

-    public int IndexOf(T item) { return indexOf(item); }

-

-

-    /// <summary>

-    /// Searches for an item in the list going backwords from the end.

-    /// </summary>

-    /// <param name="item">Item to search for.</param>

-    /// <returns>Index of of item from the end.</returns>

-    [Tested]

-    public int LastIndexOf(T item) { return indexOf(item); }

-

-

-    /// <summary>

-    /// Remove the item at a specific position of the list.

-    /// <exception cref="IndexOutOfRangeException"/> if i is negative or

-    /// &gt;= the size of the collection.

-    /// </summary>

-    /// <param name="i">The index of the item to remove.</param>

-    /// <returns>The removed item.</returns>

-    [Tested]

-    public T RemoveAt(int i)

-    {

-      if (i < 0 || i >= size)

-        throw new IndexOutOfRangeException("Index out of range for sequenced collectionvalue");

-

-      updatecheck();

-

-      T retval = array[i];

-

-      size--;

-      Array.Copy(array, i + 1, array, i, size - i);

-      array[size] = default(T);

-      raiseForRemoveAt(i, retval);

-      return retval;

-    }

-

-    /// <summary>

-    /// Remove all items in an index interval.

-    /// <exception cref="IndexOutOfRangeException"/>???. 

-    /// </summary>

-    /// <param name="start">The index of the first item to remove.</param>

-    /// <param name="count">The number of items to remove.</param>

-    [Tested]

-    public void RemoveInterval(int start, int count)

-    {

-      updatecheck();

-      checkRange(start, count);

-      Array.Copy(array, start + count, array, start, size - start - count);

-      size -= count;

-      Array.Clear(array, size, count);

-      raiseForRemoveInterval(start, count);

-    }

-

-    private void raiseForRemoveInterval(int start, int count)

-    {

-      if (ActiveEvents != 0 && count > 0)

-      {

-        raiseCollectionCleared(size == 0, count);

-        raiseCollectionChanged();

-      }

-    }

-

-    #endregion

-

-    #region IDirectedEnumerable<T> Members

-

-    /// <summary>

-    /// Create a collection containing the same items as this collection, but

-    /// whose enumerator will enumerate the items backwards. The new collection

-    /// will become invalid if the original is modified. Method typicaly used as in

-    /// <code>foreach (T x in coll.Backwards()) {...}</code>

-    /// </summary>

-    /// <returns>The backwards collection.</returns>

-    [Tested]

-    IDirectedEnumerable<T> IDirectedEnumerable<T>.Backwards()

-    { return Backwards(); }

-

-    #endregion

-

-    #region ICloneable Members

-

-    /// <summary>

-    /// Make a shallow copy of this SortedArray.

-    /// </summary>

-    /// <returns></returns>

-    public virtual object Clone()

-    {

-      SortedArray<T> clone = new SortedArray<T>(size, comparer, itemequalityComparer);

-      clone.AddSorted(this);

-      return clone;

-    }

-

-    #endregion

-

-  }

+/*
+ Copyright (c) 2003-2006 Niels Kokholm and Peter Sestoft
+ Permission is hereby granted, free of charge, to any person obtaining a copy
+ of this software and associated documentation files (the "Software"), to deal
+ in the Software without restriction, including without limitation the rights
+ to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ copies of the Software, and to permit persons to whom the Software is
+ furnished to do so, subject to the following conditions:
+ 
+ The above copyright notice and this permission notice shall be included in
+ all copies or substantial portions of the Software.
+ 
+ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ SOFTWARE.
+*/
+
+using System;
+using System.Diagnostics;
+using SCG = System.Collections.Generic;
+namespace C5
+{
+  /// <summary>
+  /// A collection class implementing a sorted dynamic array data structure.
+  /// </summary>
+  [Serializable]
+  public class SortedArray<T> : ArrayBase<T>, IIndexedSorted<T>
+  {
+    #region Features
+    /// <summary>
+    /// A debugging artifact. To be removed.
+    /// </summary>
+    [Flags]
+    public enum Feature : short
+    {
+      /// <summary>
+      /// A debugging artifact. To be removed.
+      /// </summary>
+      Standard = 0
+    }
+
+
+    static Feature features = Feature.Standard;
+
+
+    /// <summary>
+    /// A debugging artifact. To be removed.
+    /// </summary>
+    /// <value></value>
+    public static Feature Features { get { return features; } }
+
+    #endregion
+
+    #region Events
+
+    /// <summary>
+    ///
+    /// </summary>
+    /// <value></value>
+    public override EventTypeEnum ListenableEvents { get { return EventTypeEnum.Basic; } }
+
+    #endregion
+
+    #region Fields
+
+    SCG.IComparer<T> comparer;
+
+    #endregion
+
+    #region Util
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item">The item to search for</param>
+    /// <param name="mid">The least index, mid, for which array[mid] >= item</param>
+    /// <returns>True if item found</returns>
+    private bool binarySearch(T item, out int mid)
+    {
+      int bot = 0, top = size;
+
+      mid = top / 2;
+      while (top > bot)
+      {
+        int c;
+
+        if ((c = comparer.Compare(array[mid], item)) == 0)
+          return true;
+
+        if (c > 0)
+        { top = mid; }
+        else
+        { bot = mid + 1; }
+
+        mid = (bot + top) / 2;
+      }
+
+      return false;
+    }
+
+    private int indexOf(T item)
+    {
+      int ind;
+
+      if (binarySearch(item, out ind))
+        return ind;
+
+      return ~ind;
+    }
+
+    #endregion
+
+    #region Constructors
+
+    /// <summary>
+    /// Create a dynamic sorted array with a natural comparer
+    /// (and item equalityComparer,  assumed compatible)
+    /// </summary>
+    /// <exception cref="NotComparableException">If <code>T</code> is not comparable.
+    /// </exception>
+    public SortedArray() : this(8) { }
+
+
+    /// <summary>
+    /// Create a dynamic sorted array with a natural comparer 
+    /// (and item equalityComparer,  assumed compatible)
+    /// and prescribed initial capacity.
+    /// </summary>
+    /// <exception cref="NotComparableException">If <code>T</code> is not comparable.
+    /// </exception>
+    /// <param name="capacity">The capacity</param>
+    public SortedArray(int capacity)
+      : this(capacity, Comparer<T>.Default, EqualityComparer<T>.Default) { }
+
+
+    /// <summary>
+    /// Create a dynamic sorted array with an external comparer.
+    /// <para>The itemequalityComparer will be compatible 
+    /// <see cref="T:C5.ComparerZeroHashCodeEqualityComparer`1"/> since the 
+    /// default equalityComparer for T (<see cref="P:C5.EqualityComparer`1.Default"/>)
+    /// is unlikely to be compatible with the external comparer. This makes the
+    /// array inadequate for use as item in a collection of unsequenced or sequenced sets or bags
+    /// (<see cref="T:C5.ICollection`1"/> and <see cref="T:C5.ISequenced`1"/>)
+    /// </para>
+    /// </summary>
+    /// <param name="comparer">The comparer</param>
+    public SortedArray(SCG.IComparer<T> comparer)
+      : this(8, comparer) { }
+
+    /// <summary>
+    /// Create a dynamic sorted array with an external comparer
+    /// and prescribed initial capacity.
+    /// <para>The itemequalityComparer will be a compatible 
+    /// <see cref="T:C5.ComparerZeroHashCodeEqualityComparer`1"/> since the 
+    /// default equalityComparer for T (<see cref="P:C5.EqualityComparer`1.Default"/>)
+    /// is unlikely to be compatible with the external comparer. This makes the
+    /// sorted array inadequate for use as item in a collection of unsequenced or sequenced sets or bags
+    /// (<see cref="T:C5.ICollection`1"/> and <see cref="T:C5.ISequenced`1"/>)
+    /// </para>
+    /// </summary>
+    /// <param name="capacity">The capacity</param>
+    /// <param name="comparer">The comparer</param>
+    public SortedArray(int capacity, SCG.IComparer<T> comparer)
+      : this(capacity, comparer, new ComparerZeroHashCodeEqualityComparer<T>(comparer)) { }
+
+    /// <summary>
+    /// Create a dynamic sorted array with an external comparer, an external item equalityComparer
+    /// and prescribed initial capacity. This is the constructor to use if the collection 
+    /// will be used as item in a hash table based collection.
+    /// </summary>
+    /// <param name="capacity">The capacity</param>
+    /// <param name="comparer">The item comparer</param>
+    /// <param name="equalityComparer">The item equalityComparer (assumed compatible)</param>
+    public SortedArray(int capacity, SCG.IComparer<T> comparer, SCG.IEqualityComparer<T> equalityComparer)
+      : base(capacity, equalityComparer)
+    {
+      if (comparer == null)
+        throw new NullReferenceException("Comparer cannot be null");
+      this.comparer = comparer;
+    }
+
+    #endregion
+
+    #region IIndexedSorted<T> Members
+
+    /// <summary>
+    /// Determine the number of items at or above a supplied threshold.
+    /// </summary>
+    /// <param name="bot">The lower bound (inclusive)</param>
+    /// <returns>The number of matcing items.</returns>
+    [Tested]
+    public int CountFrom(T bot)
+    {
+      int lo;
+
+      binarySearch(bot, out lo);
+      return size - lo;
+    }
+
+
+    /// <summary>
+    /// Determine the number of items between two supplied thresholds.
+    /// </summary>
+    /// <param name="bot">The lower bound (inclusive)</param>
+    /// <param name="top">The upper bound (exclusive)</param>
+    /// <returns>The number of matcing items.</returns>
+    [Tested]
+    public int CountFromTo(T bot, T top)
+    {
+      int lo, hi;
+
+      binarySearch(bot, out lo);
+      binarySearch(top, out hi);
+      return hi > lo ? hi - lo : 0;
+    }
+
+
+    /// <summary>
+    /// Determine the number of items below a supplied threshold.
+    /// </summary>
+    /// <param name="top">The upper bound (exclusive)</param>
+    /// <returns>The number of matcing items.</returns>
+    [Tested]
+    public int CountTo(T top)
+    {
+      int hi;
+
+      binarySearch(top, out hi);
+      return hi;
+    }
+
+
+    /// <summary>
+    /// Query this sorted collection for items greater than or equal to a supplied value.
+    /// </summary>
+    /// <param name="bot">The lower bound (inclusive).</param>
+    /// <returns>The result directed collection.</returns>
+    [Tested]
+    public IDirectedCollectionValue<T> RangeFrom(T bot)
+    {
+      int lo;
+
+      binarySearch(bot, out lo);
+      return new Range(this, lo, size - lo, true);
+    }
+
+
+    /// <summary>
+    /// Query this sorted collection for items between two supplied values.
+    /// </summary>
+    /// <param name="bot">The lower bound (inclusive).</param>
+    /// <param name="top">The upper bound (exclusive).</param>
+    /// <returns>The result directed collection.</returns>
+    [Tested]
+    public IDirectedCollectionValue<T> RangeFromTo(T bot, T top)
+    {
+      int lo, hi;
+
+      binarySearch(bot, out lo);
+      binarySearch(top, out hi);
+
+      int sz = hi - lo;
+
+      return new Range(this, lo, sz, true);
+    }
+
+
+    /// <summary>
+    /// Query this sorted collection for items less than a supplied value.
+    /// </summary>
+    /// <param name="top">The upper bound (exclusive).</param>
+    /// <returns>The result directed collection.</returns>
+    [Tested]
+    public IDirectedCollectionValue<T> RangeTo(T top)
+    {
+      int hi;
+
+      binarySearch(top, out hi);
+      return new Range(this, 0, hi, true);
+    }
+
+
+    /// <summary>
+    /// Create a new indexed sorted collection consisting of the items of this
+    /// indexed sorted collection satisfying a certain predicate.
+    /// </summary>
+    /// <param name="f">The filter delegate defining the predicate.</param>
+    /// <returns>The new indexed sorted collection.</returns>
+    [Tested]
+    public IIndexedSorted<T> FindAll(Fun<T, bool> f)
+    {
+      SortedArray<T> res = new SortedArray<T>(comparer);
+      int j = 0, rescap = res.array.Length;
+
+      for (int i = 0; i < size; i++)
+      {
+        T a = array[i];
+
+        if (f(a))
+        {
+          if (j == rescap) res.expand(rescap = 2 * rescap, j);
+
+          res.array[j++] = a;
+        }
+      }
+
+      res.size = j;
+      return res;
+    }
+
+
+    /// <summary>
+    /// Create a new indexed sorted collection consisting of the results of
+    /// mapping all items of this list.
+    /// <exception cref="ArgumentException"/> if the map is not increasing over 
+    /// the items of this collection (with respect to the two given comparison 
+    /// relations).
+    /// </summary>
+    /// <param name="m">The delegate definging the map.</param>
+    /// <param name="c">The comparion relation to use for the result.</param>
+    /// <returns>The new sorted collection.</returns>
+    [Tested]
+    public IIndexedSorted<V> Map<V>(Fun<T, V> m, SCG.IComparer<V> c)
+    {
+      SortedArray<V> res = new SortedArray<V>(size, c);
+
+      if (size > 0)
+      {
+        V oldv = res.array[0] = m(array[0]), newv;
+
+        for (int i = 1; i < size; i++)
+        {
+          if (c.Compare(oldv, newv = res.array[i] = m(array[i])) >= 0)
+            throw new ArgumentException("mapper not monotonic");
+
+          oldv = newv;
+        }
+      }
+
+      res.size = size;
+      return res;
+    }
+
+    #endregion
+
+    #region ISorted<T> Members
+
+    /// <summary>
+    /// Find the strict predecessor of item in the sorted array,
+    /// that is, the greatest item in the collection smaller than the item.
+    /// </summary>
+    /// <param name="item">The item to find the predecessor for.</param>
+    /// <param name="res">The predecessor, if any; otherwise the default value for T.</param>
+    /// <returns>True if item has a predecessor; otherwise false.</returns>
+    public bool TryPredecessor(T item, out T res)
+    {
+        int lo;
+        binarySearch(item, out lo);
+        if (lo == 0)
+        {
+            res = default(T);
+            return false;
+        }
+        else
+        {
+            res = array[lo - 1];
+            return true;
+        }
+    }
+
+
+    /// <summary>
+    /// Find the strict successor of item in the sorted array,
+    /// that is, the least item in the collection greater than the supplied value.
+    /// </summary>
+    /// <param name="item">The item to find the successor for.</param>
+    /// <param name="res">The successor, if any; otherwise the default value for T.</param>
+    /// <returns>True if item has a successor; otherwise false.</returns>
+    public bool TrySuccessor(T item, out T res)
+    {
+        int hi;
+        if (binarySearch(item, out hi)) 
+            hi++;
+        if (hi >= size)
+        {
+            res = default(T);
+            return false;
+        } else {
+            res = array[hi];
+            return true;
+        }
+    }
+
+
+    /// <summary>
+    /// Find the weak predecessor of item in the sorted array,
+    /// that is, the greatest item in the collection smaller than or equal to the item.
+    /// </summary>
+    /// <param name="item">The item to find the weak predecessor for.</param>
+    /// <param name="res">The weak predecessor, if any; otherwise the default value for T.</param>
+    /// <returns>True if item has a weak predecessor; otherwise false.</returns>
+    public bool TryWeakPredecessor(T item, out T res)
+    {
+        int lo;
+
+        if (!binarySearch(item, out lo)) 
+            lo--;
+
+        if (lo < 0)
+        {
+            res = default(T);
+            return false;
+        }
+        else
+        {
+            res = array[lo];
+            return true;
+        }
+    }
+
+
+    /// <summary>
+    /// Find the weak successor of item in the sorted array,
+    /// that is, the least item in the collection greater than or equal to the supplied value.
+    /// </summary>
+    /// <param name="item">The item to find the weak successor for.</param>
+    /// <param name="res">The weak successor, if any; otherwise the default value for T.</param>
+    /// <returns>True if item has a weak successor; otherwise false.</returns>
+    public bool TryWeakSuccessor(T item, out T res)
+    {
+        int hi;
+
+        binarySearch(item, out hi);
+        if (hi >= size)
+        {
+            res = default(T);
+            return false;
+        }
+        else
+        {
+            res = array[hi];
+            return true;
+        }
+    }
+
+
+    /// <summary>
+    /// Find the strict predecessor in the sorted collection of a particular value,
+    /// i.e. the largest item in the collection less than the supplied value.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if no such element exists (the
+    /// supplied  value is less than or equal to the minimum of this collection.)</exception>
+    /// <param name="item">The item to find the predecessor for.</param>
+    /// <returns>The predecessor.</returns>
+    [Tested]
+    public T Predecessor(T item)
+    {
+      int lo;
+
+      binarySearch(item, out lo);
+      if (lo == 0)
+        throw new NoSuchItemException();
+
+      return array[lo - 1];
+    }
+
+
+    /// <summary>
+    /// Find the strict successor in the sorted collection of a particular value,
+    /// i.e. the least item in the collection greater than the supplied value.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if no such element exists (the
+    /// supplied  value is greater than or equal to the maximum of this collection.)</exception>
+    /// <param name="item">The item to find the successor for.</param>
+    /// <returns>The successor.</returns>
+    [Tested]
+    public T Successor(T item)
+    {
+      int hi;
+
+      if (binarySearch(item, out hi)) hi++;
+
+      if (hi >= size)
+        throw new NoSuchItemException();
+
+      return array[hi];
+    }
+
+
+    /// <summary>
+    /// Find the weak predecessor in the sorted collection of a particular value,
+    /// i.e. the largest item in the collection less than or equal to the supplied value.
+    /// <exception cref="NoSuchItemException"/> if no such element exists (the
+    /// supplied  value is less than the minimum of this collection.)
+    /// </summary>
+    /// <param name="item">The item to find the weak predecessor for.</param>
+    /// <returns>The weak predecessor.</returns>
+    [Tested]
+    public T WeakPredecessor(T item)
+    {
+      int lo;
+
+      if (!binarySearch(item, out lo)) lo--;
+
+      if (lo < 0)
+        throw new NoSuchItemException();
+
+      return array[lo];
+    }
+
+
+    /// <summary>
+    /// Find the weak successor in the sorted collection of a particular value,
+    /// i.e. the least item in the collection greater than or equal to the supplied value.
+    /// </summary>
+    /// <exception cref="NoSuchItemException"> if no such element exists (the
+    /// supplied  value is greater than the maximum of this collection.)</exception>
+    /// <param name="item">The item to find the weak successor for.</param>
+    /// <returns>The weak successor.</returns>
+    [Tested]
+    public T WeakSuccessor(T item)
+    {
+      int hi;
+
+      binarySearch(item, out hi);
+      if (hi >= size)
+        throw new NoSuchItemException();
+
+      return array[hi];
+    }
+
+
+    /// <summary>
+    /// Perform a search in the sorted collection for the ranges in which a
+    /// non-increasing (i.e. weakly decrerasing) function from the item type to 
+    /// <code>int</code> is
+    /// negative, zero respectively positive. If the supplied cut function is
+    /// not non-increasing, the result of this call is undefined.
+    /// </summary>
+    /// <param name="c">The cut function <code>T</code> to <code>int</code>, given
+    /// as an <code>IComparable&lt;T&gt;</code> object, where the cut function is
+    /// the <code>c.CompareTo(T that)</code> method.</param>
+    /// <param name="low">Returns the largest item in the collection, where the
+    /// cut function is positive (if any).</param>
+    /// <param name="lowIsValid">True if the cut function is positive somewhere
+    /// on this collection.</param>
+    /// <param name="high">Returns the least item in the collection, where the
+    /// cut function is negative (if any).</param>
+    /// <param name="highIsValid">True if the cut function is negative somewhere
+    /// on this collection.</param>
+    /// <returns></returns>
+    [Tested]
+    public bool Cut(IComparable<T> c, out T low, out bool lowIsValid, out T high, out bool highIsValid)
+    {
+      int lbest = -1, rbest = size;
+
+      low = default(T);
+      lowIsValid = false;
+      high = default(T);
+      highIsValid = false;
+
+      int bot = 0, top = size, mid, comp = -1, sol;
+
+      mid = top / 2;
+      while (top > bot)
+      {
+        if ((comp = c.CompareTo(array[mid])) == 0)
+          break;
+
+        if (comp < 0)
+        { rbest = top = mid; }
+        else
+        { lbest = mid; bot = mid + 1; }
+
+        mid = (bot + top) / 2;
+      }
+
+      if (comp != 0)
+      {
+        if (lbest >= 0) { lowIsValid = true; low = array[lbest]; }
+
+        if (rbest < size) { highIsValid = true; high = array[rbest]; }
+
+        return false;
+      }
+
+      sol = mid;
+      bot = sol - 1;
+
+      //Invariant: c.Compare(array[x]) < 0  when rbest <= x < size 
+      //           c.Compare(array[x]) >= 0 when x < bot)
+      //(Assuming c.Compare monotonic)
+      while (rbest > bot)
+      {
+        mid = (bot + rbest) / 2;
+        if (c.CompareTo(array[mid]) < 0)
+        { rbest = mid; }
+        else
+        { bot = mid + 1; }
+      }
+
+      if (rbest < size) { highIsValid = true; high = array[rbest]; }
+
+      top = sol + 1;
+
+      //Invariant: c.Compare(array[x]) > 0  when 0 <= x <= lbest
+      //           c.Compare(array[x]) <= 0 when x>top)
+      //(Assuming c.Compare monotonic)
+      while (top > lbest)
+      {
+        mid = (lbest + top + 1) / 2;
+        if (c.CompareTo(array[mid]) > 0)
+        { lbest = mid; }
+        else
+        { top = mid - 1; }
+      }
+
+      if (lbest >= 0) { lowIsValid = true; low = array[lbest]; }
+
+      return true;
+    }
+
+
+    IDirectedEnumerable<T> ISorted<T>.RangeFrom(T bot)
+    { return RangeFrom(bot); }
+
+
+    IDirectedEnumerable<T> ISorted<T>.RangeFromTo(T bot, T top)
+    { return RangeFromTo(bot, top); }
+
+
+    IDirectedEnumerable<T> ISorted<T>.RangeTo(T top)
+    { return RangeTo(top); }
+
+
+    /// <summary>
+    /// Create a directed collection with the same items as this collection.
+    /// </summary>
+    /// <returns>The result directed collection.</returns>
+    [Tested]
+    public IDirectedCollectionValue<T> RangeAll()
+    { return new Range(this, 0, size, true); }
+
+
+    /// <summary>
+    /// Add all the items from another collection with an enumeration order that 
+    /// is increasing in the items.
+    /// <exception cref="ArgumentException"/> if the enumerated items turns out
+    /// not to be in increasing order.
+    /// </summary>
+    /// <param name="items">The collection to add.</param>
+    /// <typeparam name="U"></typeparam>
+    [Tested]
+    public void AddSorted<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      //Unless items have <=1 elements we would expect it to be
+      //too expensive to do repeated inserts, thus:
+      updatecheck();
+
+      int j = 0, i = 0, c = -1, itemcount = EnumerableBase<U>.countItems(items), numAdded = 0;
+      SortedArray<T> res = new SortedArray<T>(size + itemcount, comparer);
+      T lastitem = default(T);
+      T[] addedItems = new T[itemcount];
+
+      foreach (T item in items)
+      {
+        while (i < size && (c = comparer.Compare(array[i], item)) <= 0)
+        {
+          lastitem = res.array[j++] = array[i++];
+          if (c == 0)
+            goto next;
+        }
+
+        if (j > 0 && comparer.Compare(lastitem, item) >= 0)
+          throw new ArgumentException("Argument not sorted");
+
+        addedItems[numAdded++] = lastitem = res.array[j++] = item;
+      next:
+        c = -1;
+      }
+
+      while (i < size) res.array[j++] = array[i++];
+
+      size = j;
+      array = res.array;
+      raiseForAddAll(addedItems, numAdded);
+    }
+
+
+    /// <summary>
+    /// Remove all items of this collection above or at a supplied threshold.
+    /// </summary>
+    /// <param name="low">The lower threshold (inclusive).</param>
+    [Tested]
+    public void RemoveRangeFrom(T low)
+    {
+      int lowind;
+
+      binarySearch(low, out lowind);
+      if (lowind == size)
+        return;
+
+      T[] removed = new T[size - lowind];
+      Array.Copy(array, lowind, removed, 0, removed.Length);
+      Array.Reverse(removed);
+
+      Array.Clear(array, lowind, size - lowind);
+      size = lowind;
+
+      raiseForRemoveRange(removed);
+    }
+
+
+    /// <summary>
+    /// Remove all items of this collection between two supplied thresholds.
+    /// </summary>
+    /// <param name="low">The lower threshold (inclusive).</param>
+    /// <param name="hi">The upper threshold (exclusive).</param>
+    [Tested]
+    public void RemoveRangeFromTo(T low, T hi)
+    {
+      int lowind, highind;
+
+      binarySearch(low, out lowind);
+      binarySearch(hi, out highind);
+      if (highind <= lowind)
+        return;
+
+      T[] removed = new T[highind - lowind];
+      Array.Copy(array, lowind, removed, 0, removed.Length);
+      Array.Reverse(removed);
+
+      Array.Copy(array, highind, array, lowind, size - highind);
+      Array.Clear(array, size - highind + lowind, highind - lowind);
+      size -= highind - lowind;
+
+      raiseForRemoveRange(removed);
+    }
+
+
+    /// <summary>
+    /// Remove all items of this collection below a supplied threshold.
+    /// </summary>
+    /// <param name="hi">The upper threshold (exclusive).</param>
+    [Tested]
+    public void RemoveRangeTo(T hi)
+    {
+      int highind;
+
+      binarySearch(hi, out highind);
+      if (highind == 0)
+        return;
+
+      T[] removed = new T[highind];
+      Array.Copy(array, 0, removed, 0, removed.Length);
+
+      Array.Copy(array, highind, array, 0, size - highind);
+      Array.Clear(array, size - highind, highind);
+      size = size - highind;
+
+      raiseForRemoveRange(removed);
+    }
+
+    private void raiseForRemoveRange(T[] removed)
+    {
+       foreach(T item in removed)
+         raiseItemsRemoved(item, 1);
+
+       if(removed.Length > 0)
+         raiseCollectionChanged();
+    }
+
+    #endregion
+
+    #region ICollection<T> Members
+    /// <summary>
+    /// The value is symbolic indicating the type of asymptotic complexity
+    /// in terms of the size of this collection (worst-case).
+    /// </summary>
+    /// <value>Speed.Log</value>
+    [Tested]
+    public Speed ContainsSpeed { [Tested]get { return Speed.Log; } }
+
+    /// <summary>
+    /// Remove all items from this collection, resetting internal array size.
+    /// </summary>
+    [Tested]
+    override public void Clear()
+    {
+      int oldCount = size;
+      base.Clear();
+      if(oldCount > 0)
+      {
+        raiseCollectionCleared(true, oldCount);
+        raiseCollectionChanged();
+      }
+    }
+
+    /// <summary>
+    /// Check if this collection contains (an item equivalent according to the
+    /// itemequalityComparer) to a particular value.
+    /// </summary>
+    /// <param name="item">The value to check for.</param>
+    /// <returns>True if the items is in this collection.</returns>
+    [Tested]
+    public bool Contains(T item)
+    {
+      int ind;
+
+      return binarySearch(item, out ind);
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, return in the ref argument (a
+    /// binary copy of) the actual value found.
+    /// </summary>
+    /// <param name="item">The value to look for.</param>
+    /// <returns>True if the items is in this collection.</returns>
+    [Tested]
+    public bool Find(ref T item)
+    {
+      int ind;
+
+      if (binarySearch(item, out ind))
+      {
+        item = array[ind];
+        return true;
+      }
+
+      return false;
+    }
+
+
+    //This should probably just be bool Add(ref T item); !!!
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, return in the ref argument (a
+    /// binary copy of) the actual value found. Else, add the item to the collection.
+    /// </summary>
+    /// <param name="item">The value to look for.</param>
+    /// <returns>True if the item was added (hence not found).</returns>
+    [Tested]
+    public bool FindOrAdd(ref T item)
+    {
+      updatecheck();
+
+      int ind;
+
+      if (binarySearch(item, out ind))
+      {
+        item = array[ind];
+        return true;
+      }
+
+      if (size == array.Length) expand();
+
+      Array.Copy(array, ind, array, ind + 1, size - ind);
+      array[ind] = item;
+      size++;
+      raiseForAdd(item);
+      return false;
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, update the item in the collection 
+    /// to with a binary copy of the supplied value. If the collection has bag semantics,
+    /// it is implementation dependent if this updates all equivalent copies in
+    /// the collection or just one.
+    /// </summary>
+    /// <param name="item">Value to update.</param>
+    /// <returns>True if the item was found and hence updated.</returns>
+    [Tested]
+    public bool Update(T item)
+    { T olditem; return Update(item, out olditem); }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item"></param>
+    /// <param name="olditem"></param>
+    /// <returns></returns>
+    public bool Update(T item, out T olditem)
+    {
+      updatecheck();
+
+      int ind;
+
+      if (binarySearch(item, out ind))
+      {
+        olditem = array[ind];
+        array[ind] = item;
+        raiseForUpdate(item, olditem);
+        return true;
+      }
+
+      olditem = default(T);
+      return false;
+    }
+
+
+    /// <summary>
+    /// Check if this collection contains an item equivalent according to the
+    /// itemequalityComparer to a particular value. If so, update the item in the collection 
+    /// to with a binary copy of the supplied value; else add the value to the collection. 
+    /// </summary>
+    /// <param name="item">Value to add or update.</param>
+    /// <returns>True if the item was found and updated (hence not added).</returns>
+    [Tested]
+    public bool UpdateOrAdd(T item)
+    { T olditem; return UpdateOrAdd(item, out olditem); }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <param name="item"></param>
+    /// <param name="olditem"></param>
+    /// <returns></returns>
+    public bool UpdateOrAdd(T item, out T olditem)
+    {
+      updatecheck();
+
+      int ind;
+
+      if (binarySearch(item, out ind))
+      {
+        olditem = array[ind];
+        array[ind] = item;
+        raiseForUpdate(item, olditem);
+        return true;
+      }
+
+      if (size == array.Length) expand();
+
+      Array.Copy(array, ind, array, ind + 1, size - ind);
+      array[ind] = item;
+      size++;
+      olditem = default(T);
+      raiseForAdd(item);
+      return false;
+    }
+
+
+    /// <summary>
+    /// Remove a particular item from this collection. If the collection has bag
+    /// semantics only one copy equivalent to the supplied item is removed. 
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    /// <returns>True if the item was found (and removed).</returns>
+    [Tested]
+    public bool Remove(T item)
+    {
+      int ind;
+
+      updatecheck();
+      if (binarySearch(item, out ind))
+      {
+        T removeditem = array[ind];
+        Array.Copy(array, ind + 1, array, ind, size - ind - 1);
+        array[--size] = default(T);
+        raiseForRemove(removeditem);
+        return true;
+      }
+
+      return false;
+    }
+
+
+    /// <summary>
+    /// Remove a particular item from this collection if found. If the collection
+    /// has bag semantics only one copy equivalent to the supplied item is removed,
+    /// which one is implementation dependent. 
+    /// If an item was removed, report a binary copy of the actual item removed in 
+    /// the argument.
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    /// <param name="removeditem">The removed value.</param>
+    /// <returns>True if the item was found (and removed).</returns>
+    [Tested]
+    public bool Remove(T item, out T removeditem)
+    {
+      int ind;
+
+      updatecheck();
+      if (binarySearch(item, out ind))
+      {
+        removeditem = array[ind];
+        Array.Copy(array, ind + 1, array, ind, size - ind - 1);
+        array[--size] = default(T);
+        raiseForRemove(removeditem);
+        return true;
+      }
+
+      removeditem = default(T);
+      return false;
+    }
+
+
+    /// <summary>
+    /// Remove all items in another collection from this one. 
+    /// </summary>
+    /// <typeparam name="U"></typeparam>
+    /// <param name="items">The items to remove.</param>
+    [Tested]
+    public void RemoveAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      //This is O(m*logn) with n bits extra storage
+      //(Not better to collect the m items and sort them)
+      updatecheck();
+        
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(this);
+      bool mustFire = raiseHandler.MustFire;
+
+      int[] toremove = new int[(size >> 5) + 1];
+      int ind, j = 0;
+
+      foreach (T item in items)
+        if (binarySearch(item, out ind))
+          toremove[ind >> 5] |= 1 << (ind & 31);
+
+      for (int i = 0; i < size; i++)
+        if ((toremove[i >> 5] & (1 << (i & 31))) == 0)
+          array[j++] = array[i];
+        else if (mustFire)
+          raiseHandler.Remove(array[i]);
+
+      Array.Clear(array, j, size - j);
+      size = j;
+      if (mustFire)
+        raiseHandler.Raise();
+    }
+
+    /// <summary>
+    /// Remove all items not in some other collection from this one. 
+    /// </summary>
+    /// <typeparam name="U"></typeparam>
+    /// <param name="items">The items to retain.</param>
+    [Tested]
+    public void RetainAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      //This is O(m*logn) with n bits extra storage
+      //(Not better to collect the m items and sort them)
+      updatecheck();
+
+      RaiseForRemoveAllHandler raiseHandler = new RaiseForRemoveAllHandler(this);
+      bool mustFire = raiseHandler.MustFire;
+
+      int[] toretain = new int[(size >> 5) + 1];
+      int ind, j = 0;
+
+      foreach (T item in items)
+        if (binarySearch(item, out ind))
+          toretain[ind >> 5] |= 1 << (ind & 31);
+
+      for (int i = 0; i < size; i++)
+        if ((toretain[i >> 5] & (1 << (i & 31))) != 0)
+          array[j++] = array[i];
+        else if (mustFire)
+          raiseHandler.Remove(array[i]);
+
+      Array.Clear(array, j, size - j);
+      size = j;
+      if (mustFire)
+        raiseHandler.Raise();
+    }
+
+    /// <summary>
+    /// Check if this collection contains all the values in another collection.
+    /// Multiplicities are not taken into account.
+    /// </summary>
+    /// <param name="items">The </param>
+    /// <typeparam name="U"></typeparam>
+    /// <returns>True if all values in <code>items</code>is in this collection.</returns>
+    [Tested]
+    public bool ContainsAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      int tmp;
+
+      foreach (T item in items)
+        if (!binarySearch(item, out tmp))
+          return false;
+
+      return true;
+    }
+
+
+    /// <summary>
+    /// Count the number of items of the collection equal to a particular value.
+    /// Returns 0 if and only if the value is not in the collection.
+    /// </summary>
+    /// <param name="item">The value to count.</param>
+    /// <returns>The number of copies found (0 or 1).</returns>
+    [Tested]
+    public int ContainsCount(T item)
+    {
+      int tmp;
+
+      return binarySearch(item, out tmp) ? 1 : 0;
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public virtual ICollectionValue<T> UniqueItems() { return this; }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <returns></returns>
+    public virtual ICollectionValue<KeyValuePair<T, int>> ItemMultiplicities()
+    {
+      return new MultiplicityOne<T>(this);
+    }
+
+    /// <summary>
+    /// Remove all (0 or 1) items equivalent to a given value.
+    /// </summary>
+    /// <param name="item">The value to remove.</param>
+    [Tested]
+    public void RemoveAllCopies(T item) { Remove(item); }
+
+
+    /// <summary>
+    /// Check the integrity of the internal data structures of this collection.
+    /// Only avaliable in DEBUG builds???
+    /// </summary>
+    /// <returns>True if check does not fail.</returns>
+    [Tested]
+    public override bool Check()
+    {
+      bool retval = true;
+
+      if (size > array.Length)
+      {
+        Console.WriteLine("Bad size ({0}) > array.Length ({1})", size, array.Length);
+        return false;
+      }
+
+      for (int i = 0; i < size; i++)
+      {
+        if ((object)(array[i]) == null)
+        {
+          Console.WriteLine("Bad element: null at index {0}", i);
+          return false;
+        }
+
+        if (i > 0 && comparer.Compare(array[i], array[i - 1]) <= 0)
+        {
+          Console.WriteLine("Inversion at index {0}", i);
+          retval = false;
+        }
+      }
+
+      return retval;
+    }
+
+    #endregion
+
+    #region IExtensible<T> Members
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value>False since this collection has set semantics</value>
+    [Tested]
+    public bool AllowsDuplicates { [Tested]get { return false; } }
+
+    /// <summary>
+    /// By convention this is true for any collection with set semantics.
+    /// </summary>
+    /// <value>True if only one representative of a group of equal items 
+    /// is kept in the collection together with the total count.</value>
+    public virtual bool DuplicatesByCounting { get { return true; } }
+
+    /// <summary>
+    /// Add an item to this collection if possible. If this collection has set
+    /// semantics, the item will be added if not already in the collection. If
+    /// bag semantics, the item will always be added.
+    /// </summary>
+    /// <param name="item">The item to add.</param>
+    /// <returns>True if item was added.</returns>
+    [Tested]
+    public bool Add(T item)
+    {
+      updatecheck();
+
+      int ind;
+
+      if (binarySearch(item, out ind)) return false;
+
+      insert(ind, item);
+      raiseForAdd(item);
+      return true;
+    }
+
+    /// <summary>
+    /// Add an item to this collection if possible. 
+    /// </summary>
+    /// <param name="item">The item to add.</param>
+    [Tested]
+    void SCG.ICollection<T>.Add(T item)
+    {
+        Add(item);
+    }
+
+
+    /// <summary>
+    /// Add the elements from another collection with a more specialized item type 
+    /// to this collection. Since this
+    /// collection has set semantics, only items not already in the collection
+    /// will be added.
+    /// </summary>
+    /// <typeparam name="U">The type of items to add</typeparam>
+    /// <param name="items">The items to add</param>
+    [Tested]
+    public void AddAll<U>(SCG.IEnumerable<U> items) where U : T
+    {
+      int toadd = EnumerableBase<U>.countItems(items), newsize = array.Length;
+
+      while (newsize < size + toadd) { newsize *= 2; }
+
+      T[] newarr = new T[newsize];
+
+      toadd = 0;
+      foreach (T item in items) newarr[size + toadd++] = item;
+
+      Sorting.IntroSort<T>(newarr, size, toadd, comparer);
+
+      int j = 0, i = 0, numAdded = 0;
+      T lastitem = default(T);
+      T[] addedItems = new T[toadd];
+
+      //The following eliminates duplicates (including duplicates in input)
+      //while merging the old and new collection
+      for (int k = size, klimit = size + toadd; k < klimit; k++)
+      {
+        while (i < size && comparer.Compare(array[i], newarr[k]) <= 0)
+          lastitem = newarr[j++] = array[i++];
+
+        if (j == 0 || comparer.Compare(lastitem, newarr[k]) < 0)
+          addedItems[numAdded++] = lastitem = newarr[j++] = newarr[k];
+      }
+
+      while (i < size) newarr[j++] = array[i++];
+
+      Array.Clear(newarr, j, size + toadd - j);
+      size = j;
+      array = newarr;
+
+      raiseForAddAll(addedItems, numAdded);
+    }
+
+    private void raiseForAddAll(T[] addedItems, int numAdded)
+    {
+      if ((ActiveEvents & EventTypeEnum.Added) != 0)
+        for(int i = 0 ;i < numAdded; i += 1)
+          raiseItemsAdded(addedItems[i], 1);
+      if (numAdded > 0)
+        raiseCollectionChanged();
+    }
+
+    #endregion
+
+    #region IPriorityQueue<T> Members
+
+    /// <summary>
+    /// Find the current least item of this priority queue.
+    /// </summary>
+    /// <returns>The least item.</returns>
+    [Tested]
+    public T FindMin()
+    {
+      if (size == 0)
+        throw new NoSuchItemException();
+
+      return array[0];
+    }
+
+    /// <summary>
+    /// Remove the least item from this  priority queue.
+    /// </summary>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public T DeleteMin()
+    {
+      updatecheck();
+      if (size == 0)
+        throw new NoSuchItemException();
+
+      T retval = array[0];
+
+      size--;
+      Array.Copy(array, 1, array, 0, size);
+      array[size] = default(T);
+      raiseForRemove(retval);
+      return retval;
+    }
+
+
+    /// <summary>
+    /// Find the current largest item of this priority queue.
+    /// </summary>
+    /// <returns>The largest item.</returns>
+    [Tested]
+    public T FindMax()
+    {
+      if (size == 0)
+        throw new NoSuchItemException();
+
+      return array[size - 1];
+    }
+
+
+    /// <summary>
+    /// Remove the largest item from this  priority queue.
+    /// </summary>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public T DeleteMax()
+    {
+      updatecheck();
+      if (size == 0)
+        throw new NoSuchItemException();
+
+      T retval = array[size - 1];
+
+      size--;
+      array[size] = default(T);
+      raiseForRemove(retval);
+      return retval;
+    }
+
+    /// <summary>
+    /// The comparer object supplied at creation time for this collection
+    /// </summary>
+    /// <value>The comparer</value>
+    public SCG.IComparer<T> Comparer { get { return comparer; } }
+
+    #endregion
+
+    #region IIndexed<T> Members
+
+    /// <summary>
+    /// <exception cref="IndexOutOfRangeException"/> if i is negative or
+    /// &gt;= the size of the collection.
+    /// </summary>
+    /// <value>The i'th item of this list.</value>
+    /// <param name="i">the index to lookup</param>
+    [Tested]
+    public T this[int i]
+    {
+      [Tested]
+      get
+      {
+        if (i < 0 || i >= size)
+          throw new IndexOutOfRangeException();
+
+        return array[i];
+      }
+    }
+
+    /// <summary>
+    /// 
+    /// </summary>
+    /// <value></value>
+    public virtual Speed IndexingSpeed { get { return Speed.Constant; } }
+
+    /// <summary>
+    /// Searches for an item in the list going forwrds from the start.
+    /// </summary>
+    /// <param name="item">Item to search for.</param>
+    /// <returns>Index of item from start.</returns>
+    [Tested]
+    public int IndexOf(T item) { return indexOf(item); }
+
+
+    /// <summary>
+    /// Searches for an item in the list going backwords from the end.
+    /// </summary>
+    /// <param name="item">Item to search for.</param>
+    /// <returns>Index of of item from the end.</returns>
+    [Tested]
+    public int LastIndexOf(T item) { return indexOf(item); }
+
+
+    /// <summary>
+    /// Remove the item at a specific position of the list.
+    /// <exception cref="IndexOutOfRangeException"/> if i is negative or
+    /// &gt;= the size of the collection.
+    /// </summary>
+    /// <param name="i">The index of the item to remove.</param>
+    /// <returns>The removed item.</returns>
+    [Tested]
+    public T RemoveAt(int i)
+    {
+      if (i < 0 || i >= size)
+        throw new IndexOutOfRangeException("Index out of range for sequenced collectionvalue");
+
+      updatecheck();
+
+      T retval = array[i];
+
+      size--;
+      Array.Copy(array, i + 1, array, i, size - i);
+      array[size] = default(T);
+      raiseForRemoveAt(i, retval);
+      return retval;
+    }
+
+    /// <summary>
+    /// Remove all items in an index interval.
+    /// <exception cref="IndexOutOfRangeException"/>???. 
+    /// </summary>
+    /// <param name="start">The index of the first item to remove.</param>
+    /// <param name="count">The number of items to remove.</param>
+    [Tested]
+    public void RemoveInterval(int start, int count)
+    {
+      updatecheck();
+      checkRange(start, count);
+      Array.Copy(array, start + count, array, start, size - start - count);
+      size -= count;
+      Array.Clear(array, size, count);
+      raiseForRemoveInterval(start, count);
+    }
+
+    private void raiseForRemoveInterval(int start, int count)
+    {
+      if (ActiveEvents != 0 && count > 0)
+      {
+        raiseCollectionCleared(size == 0, count);
+        raiseCollectionChanged();
+      }
+    }
+
+    #endregion
+
+    #region IDirectedEnumerable<T> Members
+
+    /// <summary>
+    /// Create a collection containing the same items as this collection, but
+    /// whose enumerator will enumerate the items backwards. The new collection
+    /// will become invalid if the original is modified. Method typicaly used as in
+    /// <code>foreach (T x in coll.Backwards()) {...}</code>
+    /// </summary>
+    /// <returns>The backwards collection.</returns>
+    [Tested]
+    IDirectedEnumerable<T> IDirectedEnumerable<T>.Backwards()
+    { return Backwards(); }
+
+    #endregion
+
+    #region ICloneable Members
+
+    /// <summary>
+    /// Make a shallow copy of this SortedArray.
+    /// </summary>
+    /// <returns></returns>
+    public virtual object Clone()
+    {
+      SortedArray<T> clone = new SortedArray<T>(size, comparer, itemequalityComparer);
+      clone.AddSorted(this);
+      return clone;
+    }
+
+    #endregion
+
+  }
 }
\ No newline at end of file