Apply changes from https://github.com/mono/mono/pull/8818 to API snapshot

5 files changed, 269 insertions, 0 deletions

diff --git a/profiles/monodroid/Facades/System.Memory.cs b/profiles/monodroid/Facades/System.Memory.cs
index 4bfee25..7661799 100644
--- a/profiles/monodroid/Facades/System.Memory.cs
+++ b/profiles/monodroid/Facades/System.Memory.cs
@@ -15,10 +15,15 @@
 [assembly:System.Runtime.CompilerServices.CompilationRelaxationsAttribute(8)]
 [assembly:System.Runtime.CompilerServices.RuntimeCompatibilityAttribute(WrapNonExceptionThrows=true)]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.Binary.BinaryPrimitives))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.BuffersExtensions))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.IBufferWriter<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.IMemoryOwner<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.IPinnable))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.MemoryHandle))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.MemoryManager<>))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.MemoryPool<>))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.ReadOnlySequence<>))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.ReadOnlySequenceSegment<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.Text.Base64))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.Text.Utf8Formatter))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.Text.Utf8Parser))]
@@ -27,4 +32,6 @@
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.ReadOnlyMemory<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.ReadOnlySpan<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Runtime.InteropServices.MemoryMarshal))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Runtime.InteropServices.SequenceMarshal))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.SequencePosition))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Span<>))]
diff --git a/profiles/monodroid/mscorlib.cs b/profiles/monodroid/mscorlib.cs
index 892e2c8..ff97dad 100644
--- a/profiles/monodroid/mscorlib.cs
+++ b/profiles/monodroid/mscorlib.cs
@@ -4195,6 +4195,17 @@ namespace System
         [System.CLSCompliantAttribute(false)]
         public static bool TryParse(string s, out System.SByte result) { result = default(sbyte); throw null; }
     }
+    [System.Runtime.CompilerServices.IsReadOnlyAttribute]
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    public partial struct SequencePosition : System.IEquatable<System.SequencePosition>
+    {
+        public SequencePosition(object @object, int integer) { throw null;}
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.SequencePosition other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        public int GetInteger() { throw null; }
+        public object GetObject() { throw null; }
+    }
     [System.AttributeUsageAttribute((System.AttributeTargets)(4124), Inherited=false)]
     [System.Runtime.InteropServices.ComVisibleAttribute(true)]
     public sealed partial class SerializableAttribute : System.Attribute
@@ -5830,6 +5841,19 @@ namespace System.Buffers
         public abstract T[] Rent(int minimumLength);
         public abstract void Return(T[] array, bool clearArray=false);
     }
+    public static partial class BuffersExtensions
+    {
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static void CopyTo<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> source, System.Span<T> destination) { }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static System.Nullable<System.SequencePosition> PositionOf<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> source, T value) where T : System.IEquatable<T> { throw null; }
+        public static T[] ToArray<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> sequence) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static void Write<T>(this System.Buffers.IBufferWriter<T> writer, System.ReadOnlySpan<T> value) { }
+    }
+    public partial interface IBufferWriter<T>
+    {
+        void Advance(int count);
+        System.Memory<T> GetMemory(int sizeHint=0);
+        System.Span<T> GetSpan(int sizeHint=0);
+    }
     public partial interface IMemoryOwner<T> : System.IDisposable
     {
         System.Memory<T> Memory { get; }
@@ -5861,6 +5885,15 @@ namespace System.Buffers
         protected internal virtual bool TryGetArray(out System.ArraySegment<T> segment) { segment = default(System.ArraySegment<T>); throw null; }
         public abstract void Unpin();
     }
+    public abstract partial class MemoryPool<T> : System.IDisposable
+    {
+        protected MemoryPool() { }
+        public abstract int MaxBufferSize { get; }
+        public static System.Buffers.MemoryPool<T> Shared { get { throw null; } }
+        public void Dispose() { }
+        protected abstract void Dispose(bool disposing);
+        public abstract System.Buffers.IMemoryOwner<T> Rent(int minBufferSize=-1);
+    }
     public enum OperationStatus
     {
         DestinationTooSmall = 1,
@@ -5868,6 +5901,52 @@ namespace System.Buffers
         InvalidData = 3,
         NeedMoreData = 2,
     }
+    public abstract partial class ReadOnlySequenceSegment<T>
+    {
+        protected ReadOnlySequenceSegment() { }
+        public System.ReadOnlyMemory<T> Memory { get { throw null; } protected set { } }
+        public System.Buffers.ReadOnlySequenceSegment<T> Next { get { throw null; } protected set { } }
+        public long RunningIndex { get { throw null; } protected set { } }
+    }
+    [System.Diagnostics.DebuggerDisplayAttribute("{ToString(),raw}")]
+    [System.Diagnostics.DebuggerTypeProxyAttribute("System.Buffers.ReadOnlySequenceDebugView<T>")]
+    [System.Runtime.CompilerServices.IsReadOnlyAttribute]
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    public partial struct ReadOnlySequence<T>
+    {
+        public static readonly System.Buffers.ReadOnlySequence<T> Empty;
+        public ReadOnlySequence(System.Buffers.ReadOnlySequenceSegment<T> startSegment, int startIndex, System.Buffers.ReadOnlySequenceSegment<T> endSegment, int endIndex) { throw null;}
+        public ReadOnlySequence(System.ReadOnlyMemory<T> memory) { throw null;}
+        public ReadOnlySequence(T[] array) { throw null;}
+        public ReadOnlySequence(T[] array, int start, int length) { throw null;}
+        public System.SequencePosition End { get { throw null; } }
+        public System.ReadOnlyMemory<T> First { get { throw null; } }
+        public bool IsEmpty { get { throw null; } }
+        public bool IsSingleSegment { [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]get { throw null; } }
+        public long Length { get { throw null; } }
+        public System.SequencePosition Start { get { throw null; } }
+        public System.Buffers.ReadOnlySequence<T>.Enumerator GetEnumerator() { throw null; }
+        public System.SequencePosition GetPosition(long offset) { throw null; }
+        public System.SequencePosition GetPosition(long offset, System.SequencePosition origin) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(int start, int length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(int start, System.SequencePosition end) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start, long length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start, System.SequencePosition end) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, int length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, long length) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, System.SequencePosition end) { throw null; }
+        public override string ToString() { throw null; }
+        public bool TryGet(ref System.SequencePosition position, out System.ReadOnlyMemory<T> memory, bool advance=true) { memory = default(System.ReadOnlyMemory<T>); throw null; }
+        [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+        public partial struct Enumerator
+        {
+            public Enumerator([System.Runtime.CompilerServices.IsReadOnlyAttribute][System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> sequence) { throw null;}
+            public System.ReadOnlyMemory<T> Current { get { throw null; } }
+            public bool MoveNext() { throw null; }
+        }
+    }
     [System.Runtime.CompilerServices.IsReadOnlyAttribute]
     [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
     public partial struct StandardFormat : System.IEquatable<System.Buffers.StandardFormat>
@@ -15521,6 +15600,12 @@ namespace System.Runtime.InteropServices
         public SEHException(string message, System.Exception inner) { }
         public virtual bool CanResume() { throw null; }
     }
+    public static partial class SequenceMarshal
+    {
+        public static bool TryGetArray<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.ArraySegment<T> segment) { segment = default(System.ArraySegment<T>); throw null; }
+        public static bool TryGetReadOnlyMemory<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.ReadOnlyMemory<T> memory) { memory = default(System.ReadOnlyMemory<T>); throw null; }
+        public static bool TryGetReadOnlySequenceSegment<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.Buffers.ReadOnlySequenceSegment<T> startSegment, out int startIndex, out System.Buffers.ReadOnlySequenceSegment<T> endSegment, out int endIndex) { startSegment = default(System.Buffers.ReadOnlySequenceSegment<T>); startIndex = default(int); endSegment = default(System.Buffers.ReadOnlySequenceSegment<T>); endIndex = default(int); throw null; }
+    }
     [System.AttributeUsageAttribute((System.AttributeTargets)(1), Inherited=false)]
     [System.ObsoleteAttribute("This attribute has been deprecated.  Application Domains no longer respect Activation Context boundaries in IDispatch calls.", false)]
     [System.Runtime.InteropServices.ComVisibleAttribute(true)]
diff --git a/profiles/monotouch/Facades/System.Memory.cs b/profiles/monotouch/Facades/System.Memory.cs
index 4bfee25..7661799 100644
--- a/profiles/monotouch/Facades/System.Memory.cs
+++ b/profiles/monotouch/Facades/System.Memory.cs
@@ -15,10 +15,15 @@
 [assembly:System.Runtime.CompilerServices.CompilationRelaxationsAttribute(8)]
 [assembly:System.Runtime.CompilerServices.RuntimeCompatibilityAttribute(WrapNonExceptionThrows=true)]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.Binary.BinaryPrimitives))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.BuffersExtensions))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.IBufferWriter<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.IMemoryOwner<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.IPinnable))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.MemoryHandle))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.MemoryManager<>))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.MemoryPool<>))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.ReadOnlySequence<>))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.ReadOnlySequenceSegment<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.Text.Base64))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.Text.Utf8Formatter))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Buffers.Text.Utf8Parser))]
@@ -27,4 +32,6 @@
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.ReadOnlyMemory<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.ReadOnlySpan<>))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Runtime.InteropServices.MemoryMarshal))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Runtime.InteropServices.SequenceMarshal))]
+[assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.SequencePosition))]
 [assembly:System.Runtime.CompilerServices.TypeForwardedToAttribute(typeof(System.Span<>))]
diff --git a/profiles/monotouch/mscorlib.cs b/profiles/monotouch/mscorlib.cs
index 3de0d5c..90d94a0 100644
--- a/profiles/monotouch/mscorlib.cs
+++ b/profiles/monotouch/mscorlib.cs
@@ -4175,6 +4175,17 @@ namespace System
         [System.CLSCompliantAttribute(false)]
         public static bool TryParse(string s, out System.SByte result) { result = default(sbyte); throw null; }
     }
+    [System.Runtime.CompilerServices.IsReadOnlyAttribute]
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    public partial struct SequencePosition : System.IEquatable<System.SequencePosition>
+    {
+        public SequencePosition(object @object, int integer) { throw null;}
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.SequencePosition other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        public int GetInteger() { throw null; }
+        public object GetObject() { throw null; }
+    }
     [System.AttributeUsageAttribute((System.AttributeTargets)(4124), Inherited=false)]
     [System.Runtime.InteropServices.ComVisibleAttribute(true)]
     public sealed partial class SerializableAttribute : System.Attribute
@@ -5801,6 +5812,19 @@ namespace System.Buffers
         public abstract T[] Rent(int minimumLength);
         public abstract void Return(T[] array, bool clearArray=false);
     }
+    public static partial class BuffersExtensions
+    {
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static void CopyTo<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> source, System.Span<T> destination) { }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static System.Nullable<System.SequencePosition> PositionOf<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> source, T value) where T : System.IEquatable<T> { throw null; }
+        public static T[] ToArray<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> sequence) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static void Write<T>(this System.Buffers.IBufferWriter<T> writer, System.ReadOnlySpan<T> value) { }
+    }
+    public partial interface IBufferWriter<T>
+    {
+        void Advance(int count);
+        System.Memory<T> GetMemory(int sizeHint=0);
+        System.Span<T> GetSpan(int sizeHint=0);
+    }
     public partial interface IMemoryOwner<T> : System.IDisposable
     {
         System.Memory<T> Memory { get; }
@@ -5832,6 +5856,15 @@ namespace System.Buffers
         protected internal virtual bool TryGetArray(out System.ArraySegment<T> segment) { segment = default(System.ArraySegment<T>); throw null; }
         public abstract void Unpin();
     }
+    public abstract partial class MemoryPool<T> : System.IDisposable
+    {
+        protected MemoryPool() { }
+        public abstract int MaxBufferSize { get; }
+        public static System.Buffers.MemoryPool<T> Shared { get { throw null; } }
+        public void Dispose() { }
+        protected abstract void Dispose(bool disposing);
+        public abstract System.Buffers.IMemoryOwner<T> Rent(int minBufferSize=-1);
+    }
     public enum OperationStatus
     {
         DestinationTooSmall = 1,
@@ -5839,6 +5872,52 @@ namespace System.Buffers
         InvalidData = 3,
         NeedMoreData = 2,
     }
+    public abstract partial class ReadOnlySequenceSegment<T>
+    {
+        protected ReadOnlySequenceSegment() { }
+        public System.ReadOnlyMemory<T> Memory { get { throw null; } protected set { } }
+        public System.Buffers.ReadOnlySequenceSegment<T> Next { get { throw null; } protected set { } }
+        public long RunningIndex { get { throw null; } protected set { } }
+    }
+    [System.Diagnostics.DebuggerDisplayAttribute("{ToString(),raw}")]
+    [System.Diagnostics.DebuggerTypeProxyAttribute("System.Buffers.ReadOnlySequenceDebugView<T>")]
+    [System.Runtime.CompilerServices.IsReadOnlyAttribute]
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    public partial struct ReadOnlySequence<T>
+    {
+        public static readonly System.Buffers.ReadOnlySequence<T> Empty;
+        public ReadOnlySequence(System.Buffers.ReadOnlySequenceSegment<T> startSegment, int startIndex, System.Buffers.ReadOnlySequenceSegment<T> endSegment, int endIndex) { throw null;}
+        public ReadOnlySequence(System.ReadOnlyMemory<T> memory) { throw null;}
+        public ReadOnlySequence(T[] array) { throw null;}
+        public ReadOnlySequence(T[] array, int start, int length) { throw null;}
+        public System.SequencePosition End { get { throw null; } }
+        public System.ReadOnlyMemory<T> First { get { throw null; } }
+        public bool IsEmpty { get { throw null; } }
+        public bool IsSingleSegment { [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]get { throw null; } }
+        public long Length { get { throw null; } }
+        public System.SequencePosition Start { get { throw null; } }
+        public System.Buffers.ReadOnlySequence<T>.Enumerator GetEnumerator() { throw null; }
+        public System.SequencePosition GetPosition(long offset) { throw null; }
+        public System.SequencePosition GetPosition(long offset, System.SequencePosition origin) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(int start, int length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(int start, System.SequencePosition end) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start, long length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start, System.SequencePosition end) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, int length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, long length) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, System.SequencePosition end) { throw null; }
+        public override string ToString() { throw null; }
+        public bool TryGet(ref System.SequencePosition position, out System.ReadOnlyMemory<T> memory, bool advance=true) { memory = default(System.ReadOnlyMemory<T>); throw null; }
+        [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+        public partial struct Enumerator
+        {
+            public Enumerator([System.Runtime.CompilerServices.IsReadOnlyAttribute][System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> sequence) { throw null;}
+            public System.ReadOnlyMemory<T> Current { get { throw null; } }
+            public bool MoveNext() { throw null; }
+        }
+    }
     [System.Runtime.CompilerServices.IsReadOnlyAttribute]
     [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
     public partial struct StandardFormat : System.IEquatable<System.Buffers.StandardFormat>
@@ -14701,6 +14780,12 @@ namespace System.Runtime.InteropServices
         public SEHException(string message, System.Exception inner) { }
         public virtual bool CanResume() { throw null; }
     }
+    public static partial class SequenceMarshal
+    {
+        public static bool TryGetArray<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.ArraySegment<T> segment) { segment = default(System.ArraySegment<T>); throw null; }
+        public static bool TryGetReadOnlyMemory<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.ReadOnlyMemory<T> memory) { memory = default(System.ReadOnlyMemory<T>); throw null; }
+        public static bool TryGetReadOnlySequenceSegment<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.Buffers.ReadOnlySequenceSegment<T> startSegment, out int startIndex, out System.Buffers.ReadOnlySequenceSegment<T> endSegment, out int endIndex) { startSegment = default(System.Buffers.ReadOnlySequenceSegment<T>); startIndex = default(int); endSegment = default(System.Buffers.ReadOnlySequenceSegment<T>); endIndex = default(int); throw null; }
+    }
     [System.AttributeUsageAttribute((System.AttributeTargets)(1), Inherited=false)]
     [System.ObsoleteAttribute("This attribute has been deprecated.  Application Domains no longer respect Activation Context boundaries in IDispatch calls.", false)]
     [System.Runtime.InteropServices.ComVisibleAttribute(true)]
diff --git a/profiles/net_4_x/mscorlib.cs b/profiles/net_4_x/mscorlib.cs
index 47c6fed..e74058b 100644
--- a/profiles/net_4_x/mscorlib.cs
+++ b/profiles/net_4_x/mscorlib.cs
@@ -4239,6 +4239,17 @@ namespace System
         [System.CLSCompliantAttribute(false)]
         public static bool TryParse(string s, out System.SByte result) { result = default(sbyte); throw null; }
     }
+    [System.Runtime.CompilerServices.IsReadOnlyAttribute]
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    public partial struct SequencePosition : System.IEquatable<System.SequencePosition>
+    {
+        public SequencePosition(object @object, int integer) { throw null;}
+        public override bool Equals(object obj) { throw null; }
+        public bool Equals(System.SequencePosition other) { throw null; }
+        public override int GetHashCode() { throw null; }
+        public int GetInteger() { throw null; }
+        public object GetObject() { throw null; }
+    }
     [System.AttributeUsageAttribute((System.AttributeTargets)(4124), Inherited=false)]
     [System.Runtime.InteropServices.ComVisibleAttribute(true)]
     public sealed partial class SerializableAttribute : System.Attribute
@@ -5863,6 +5874,19 @@ namespace System.Buffers
         public abstract T[] Rent(int minimumLength);
         public abstract void Return(T[] array, bool clearArray=false);
     }
+    public static partial class BuffersExtensions
+    {
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static void CopyTo<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> source, System.Span<T> destination) { }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static System.Nullable<System.SequencePosition> PositionOf<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> source, T value) where T : System.IEquatable<T> { throw null; }
+        public static T[] ToArray<T>([System.Runtime.CompilerServices.IsReadOnlyAttribute]this [System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> sequence) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public static void Write<T>(this System.Buffers.IBufferWriter<T> writer, System.ReadOnlySpan<T> value) { }
+    }
+    public partial interface IBufferWriter<T>
+    {
+        void Advance(int count);
+        System.Memory<T> GetMemory(int sizeHint=0);
+        System.Span<T> GetSpan(int sizeHint=0);
+    }
     public partial interface IMemoryOwner<T> : System.IDisposable
     {
         System.Memory<T> Memory { get; }
@@ -5894,6 +5918,15 @@ namespace System.Buffers
         protected internal virtual bool TryGetArray(out System.ArraySegment<T> segment) { segment = default(System.ArraySegment<T>); throw null; }
         public abstract void Unpin();
     }
+    public abstract partial class MemoryPool<T> : System.IDisposable
+    {
+        protected MemoryPool() { }
+        public abstract int MaxBufferSize { get; }
+        public static System.Buffers.MemoryPool<T> Shared { get { throw null; } }
+        public void Dispose() { }
+        protected abstract void Dispose(bool disposing);
+        public abstract System.Buffers.IMemoryOwner<T> Rent(int minBufferSize=-1);
+    }
     public enum OperationStatus
     {
         DestinationTooSmall = 1,
@@ -5901,6 +5934,52 @@ namespace System.Buffers
         InvalidData = 3,
         NeedMoreData = 2,
     }
+    public abstract partial class ReadOnlySequenceSegment<T>
+    {
+        protected ReadOnlySequenceSegment() { }
+        public System.ReadOnlyMemory<T> Memory { get { throw null; } protected set { } }
+        public System.Buffers.ReadOnlySequenceSegment<T> Next { get { throw null; } protected set { } }
+        public long RunningIndex { get { throw null; } protected set { } }
+    }
+    [System.Diagnostics.DebuggerDisplayAttribute("{ToString(),raw}")]
+    [System.Diagnostics.DebuggerTypeProxyAttribute("System.Buffers.ReadOnlySequenceDebugView<T>")]
+    [System.Runtime.CompilerServices.IsReadOnlyAttribute]
+    [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+    public partial struct ReadOnlySequence<T>
+    {
+        public static readonly System.Buffers.ReadOnlySequence<T> Empty;
+        public ReadOnlySequence(System.Buffers.ReadOnlySequenceSegment<T> startSegment, int startIndex, System.Buffers.ReadOnlySequenceSegment<T> endSegment, int endIndex) { throw null;}
+        public ReadOnlySequence(System.ReadOnlyMemory<T> memory) { throw null;}
+        public ReadOnlySequence(T[] array) { throw null;}
+        public ReadOnlySequence(T[] array, int start, int length) { throw null;}
+        public System.SequencePosition End { get { throw null; } }
+        public System.ReadOnlyMemory<T> First { get { throw null; } }
+        public bool IsEmpty { get { throw null; } }
+        public bool IsSingleSegment { [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]get { throw null; } }
+        public long Length { get { throw null; } }
+        public System.SequencePosition Start { get { throw null; } }
+        public System.Buffers.ReadOnlySequence<T>.Enumerator GetEnumerator() { throw null; }
+        public System.SequencePosition GetPosition(long offset) { throw null; }
+        public System.SequencePosition GetPosition(long offset, System.SequencePosition origin) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(int start, int length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(int start, System.SequencePosition end) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start, long length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(long start, System.SequencePosition end) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, int length) { throw null; }
+        public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, long length) { throw null; }
+        [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.AggressiveInlining)]public System.Buffers.ReadOnlySequence<T> Slice(System.SequencePosition start, System.SequencePosition end) { throw null; }
+        public override string ToString() { throw null; }
+        public bool TryGet(ref System.SequencePosition position, out System.ReadOnlyMemory<T> memory, bool advance=true) { memory = default(System.ReadOnlyMemory<T>); throw null; }
+        [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
+        public partial struct Enumerator
+        {
+            public Enumerator([System.Runtime.CompilerServices.IsReadOnlyAttribute][System.Runtime.InteropServices.In]ref System.Buffers.ReadOnlySequence<T> sequence) { throw null;}
+            public System.ReadOnlyMemory<T> Current { get { throw null; } }
+            public bool MoveNext() { throw null; }
+        }
+    }
     [System.Runtime.CompilerServices.IsReadOnlyAttribute]
     [System.Runtime.InteropServices.StructLayoutAttribute(System.Runtime.InteropServices.LayoutKind.Sequential)]
     public partial struct StandardFormat : System.IEquatable<System.Buffers.StandardFormat>
@@ -15623,6 +15702,12 @@ namespace System.Runtime.InteropServices
         public SEHException(string message, System.Exception inner) { }
         public virtual bool CanResume() { throw null; }
     }
+    public static partial class SequenceMarshal
+    {
+        public static bool TryGetArray<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.ArraySegment<T> segment) { segment = default(System.ArraySegment<T>); throw null; }
+        public static bool TryGetReadOnlyMemory<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.ReadOnlyMemory<T> memory) { memory = default(System.ReadOnlyMemory<T>); throw null; }
+        public static bool TryGetReadOnlySequenceSegment<T>(System.Buffers.ReadOnlySequence<T> sequence, out System.Buffers.ReadOnlySequenceSegment<T> startSegment, out int startIndex, out System.Buffers.ReadOnlySequenceSegment<T> endSegment, out int endIndex) { startSegment = default(System.Buffers.ReadOnlySequenceSegment<T>); startIndex = default(int); endSegment = default(System.Buffers.ReadOnlySequenceSegment<T>); endIndex = default(int); throw null; }
+    }
     [System.AttributeUsageAttribute((System.AttributeTargets)(1), Inherited=false)]
     [System.ObsoleteAttribute("This attribute has been deprecated.  Application Domains no longer respect Activation Context boundaries in IDispatch calls.", false)]
     [System.Runtime.InteropServices.ComVisibleAttribute(true)]