Merge branch 'master' of https://github.com/Tencent/rapidjson into id-and-ref

3 files changed, 867 insertions, 122 deletions

diff --git a/include/rapidjson/allocators.h b/include/rapidjson/allocators.h
index 44ec5295..12bc5baf 100644
--- a/include/rapidjson/allocators.h
+++ b/include/rapidjson/allocators.h
@@ -16,6 +16,13 @@
 #define RAPIDJSON_ALLOCATORS_H_
 
 #include "rapidjson.h"
+#include "internal/meta.h"
+
+#include <memory>
+
+#if RAPIDJSON_HAS_CXX11
+#include <type_traits>
+#endif
 
 RAPIDJSON_NAMESPACE_BEGIN
 
@@ -89,7 +96,14 @@ public:
         }
         return RAPIDJSON_REALLOC(originalPtr, newSize);
     }
-    static void Free(void *ptr) { RAPIDJSON_FREE(ptr); }
+    static void Free(void *ptr) RAPIDJSON_NOEXCEPT { RAPIDJSON_FREE(ptr); }
+
+    bool operator==(const CrtAllocator&) const RAPIDJSON_NOEXCEPT {
+        return true;
+    }
+    bool operator!=(const CrtAllocator&) const RAPIDJSON_NOEXCEPT {
+        return false;
+    }
 };
 
 ///////////////////////////////////////////////////////////////////////////////
@@ -113,16 +127,64 @@ public:
 */
 template <typename BaseAllocator = CrtAllocator>
 class MemoryPoolAllocator {
+    //! Chunk header for perpending to each chunk.
+    /*! Chunks are stored as a singly linked list.
+    */
+    struct ChunkHeader {
+        size_t capacity;    //!< Capacity of the chunk in bytes (excluding the header itself).
+        size_t size;        //!< Current size of allocated memory in bytes.
+        ChunkHeader *next;  //!< Next chunk in the linked list.
+    };
+
+    struct SharedData {
+        ChunkHeader *chunkHead;  //!< Head of the chunk linked-list. Only the head chunk serves allocation.
+        BaseAllocator* ownBaseAllocator; //!< base allocator created by this object.
+        size_t refcount;
+        bool ownBuffer;
+    };
+
+    static const size_t SIZEOF_SHARED_DATA = RAPIDJSON_ALIGN(sizeof(SharedData));
+    static const size_t SIZEOF_CHUNK_HEADER = RAPIDJSON_ALIGN(sizeof(ChunkHeader));
+
+    static inline ChunkHeader *GetChunkHead(SharedData *shared)
+    {
+        return reinterpret_cast<ChunkHeader*>(reinterpret_cast<uint8_t*>(shared) + SIZEOF_SHARED_DATA);
+    }
+    static inline uint8_t *GetChunkBuffer(SharedData *shared)
+    {
+        return reinterpret_cast<uint8_t*>(shared->chunkHead) + SIZEOF_CHUNK_HEADER;
+    }
+
+    static const size_t kDefaultChunkCapacity = RAPIDJSON_ALLOCATOR_DEFAULT_CHUNK_CAPACITY; //!< Default chunk capacity.
+
 public:
     static const bool kNeedFree = false;    //!< Tell users that no need to call Free() with this allocator. (concept Allocator)
+    static const bool kRefCounted = true;   //!< Tell users that this allocator is reference counted on copy
 
     //! Constructor with chunkSize.
     /*! \param chunkSize The size of memory chunk. The default is kDefaultChunkSize.
         \param baseAllocator The allocator for allocating memory chunks.
     */
+    explicit
     MemoryPoolAllocator(size_t chunkSize = kDefaultChunkCapacity, BaseAllocator* baseAllocator = 0) : 
-        chunkHead_(0), chunk_capacity_(chunkSize), userBuffer_(0), baseAllocator_(baseAllocator), ownBaseAllocator_(0)
+        chunk_capacity_(chunkSize),
+        baseAllocator_(baseAllocator ? baseAllocator : RAPIDJSON_NEW(BaseAllocator)()),
+        shared_(static_cast<SharedData*>(baseAllocator_ ? baseAllocator_->Malloc(SIZEOF_SHARED_DATA + SIZEOF_CHUNK_HEADER) : 0))
     {
+        RAPIDJSON_ASSERT(baseAllocator_ != 0);
+        RAPIDJSON_ASSERT(shared_ != 0);
+        if (baseAllocator) {
+            shared_->ownBaseAllocator = 0;
+        }
+        else {
+            shared_->ownBaseAllocator = baseAllocator_;
+        }
+        shared_->chunkHead = GetChunkHead(shared_);
+        shared_->chunkHead->capacity = 0;
+        shared_->chunkHead->size = 0;
+        shared_->chunkHead->next = 0;
+        shared_->ownBuffer = true;
+        shared_->refcount = 1;
     }
 
     //! Constructor with user-supplied buffer.
@@ -136,41 +198,101 @@ public:
         \param baseAllocator The allocator for allocating memory chunks.
     */
     MemoryPoolAllocator(void *buffer, size_t size, size_t chunkSize = kDefaultChunkCapacity, BaseAllocator* baseAllocator = 0) :
-        chunkHead_(0), chunk_capacity_(chunkSize), userBuffer_(buffer), baseAllocator_(baseAllocator), ownBaseAllocator_(0)
+        chunk_capacity_(chunkSize),
+        baseAllocator_(baseAllocator),
+        shared_(static_cast<SharedData*>(AlignBuffer(buffer, size)))
+    {
+        RAPIDJSON_ASSERT(size >= SIZEOF_SHARED_DATA + SIZEOF_CHUNK_HEADER);
+        shared_->chunkHead = GetChunkHead(shared_);
+        shared_->chunkHead->capacity = size - SIZEOF_SHARED_DATA - SIZEOF_CHUNK_HEADER;
+        shared_->chunkHead->size = 0;
+        shared_->chunkHead->next = 0;
+        shared_->ownBaseAllocator = 0;
+        shared_->ownBuffer = false;
+        shared_->refcount = 1;
+    }
+
+    MemoryPoolAllocator(const MemoryPoolAllocator& rhs) RAPIDJSON_NOEXCEPT :
+        chunk_capacity_(rhs.chunk_capacity_),
+        baseAllocator_(rhs.baseAllocator_),
+        shared_(rhs.shared_)
+    {
+        RAPIDJSON_NOEXCEPT_ASSERT(shared_->refcount > 0);
+        ++shared_->refcount;
+    }
+    MemoryPoolAllocator& operator=(const MemoryPoolAllocator& rhs) RAPIDJSON_NOEXCEPT
     {
-        RAPIDJSON_ASSERT(buffer != 0);
-        RAPIDJSON_ASSERT(size > sizeof(ChunkHeader));
-        chunkHead_ = reinterpret_cast<ChunkHeader*>(buffer);
-        chunkHead_->capacity = size - sizeof(ChunkHeader);
-        chunkHead_->size = 0;
-        chunkHead_->next = 0;
+        RAPIDJSON_NOEXCEPT_ASSERT(rhs.shared_->refcount > 0);
+        ++rhs.shared_->refcount;
+        this->~MemoryPoolAllocator();
+        baseAllocator_ = rhs.baseAllocator_;
+        chunk_capacity_ = rhs.chunk_capacity_;
+        shared_ = rhs.shared_;
+        return *this;
     }
 
+#if RAPIDJSON_HAS_CXX11_RVALUE_REFS
+    MemoryPoolAllocator(MemoryPoolAllocator&& rhs) RAPIDJSON_NOEXCEPT :
+        chunk_capacity_(rhs.chunk_capacity_),
+        baseAllocator_(rhs.baseAllocator_),
+        shared_(rhs.shared_)
+    {
+        RAPIDJSON_NOEXCEPT_ASSERT(rhs.shared_->refcount > 0);
+        rhs.shared_ = 0;
+    }
+    MemoryPoolAllocator& operator=(MemoryPoolAllocator&& rhs) RAPIDJSON_NOEXCEPT
+    {
+        RAPIDJSON_NOEXCEPT_ASSERT(rhs.shared_->refcount > 0);
+        this->~MemoryPoolAllocator();
+        baseAllocator_ = rhs.baseAllocator_;
+        chunk_capacity_ = rhs.chunk_capacity_;
+        shared_ = rhs.shared_;
+        rhs.shared_ = 0;
+        return *this;
+    }
+#endif
+
     //! Destructor.
     /*! This deallocates all memory chunks, excluding the user-supplied buffer.
     */
-    ~MemoryPoolAllocator() {
+    ~MemoryPoolAllocator() RAPIDJSON_NOEXCEPT {
+        if (!shared_) {
+            // do nothing if moved
+            return;
+        }
+        if (shared_->refcount > 1) {
+            --shared_->refcount;
+            return;
+        }
         Clear();
-        RAPIDJSON_DELETE(ownBaseAllocator_);
+        BaseAllocator *a = shared_->ownBaseAllocator;
+        if (shared_->ownBuffer) {
+            baseAllocator_->Free(shared_);
+        }
+        RAPIDJSON_DELETE(a);
     }
 
-    //! Deallocates all memory chunks, excluding the user-supplied buffer.
-    void Clear() {
-        while (chunkHead_ && chunkHead_ != userBuffer_) {
-            ChunkHeader* next = chunkHead_->next;
-            baseAllocator_->Free(chunkHead_);
-            chunkHead_ = next;
+    //! Deallocates all memory chunks, excluding the first/user one.
+    void Clear() RAPIDJSON_NOEXCEPT {
+        RAPIDJSON_NOEXCEPT_ASSERT(shared_->refcount > 0);
+        for (;;) {
+            ChunkHeader* c = shared_->chunkHead;
+            if (!c->next) {
+                break;
+            }
+            shared_->chunkHead = c->next;
+            baseAllocator_->Free(c);
         }
-        if (chunkHead_ && chunkHead_ == userBuffer_)
-            chunkHead_->size = 0; // Clear user buffer
+        shared_->chunkHead->size = 0;
     }
 
     //! Computes the total capacity of allocated memory chunks.
     /*! \return total capacity in bytes.
     */
-    size_t Capacity() const {
+    size_t Capacity() const RAPIDJSON_NOEXCEPT {
+        RAPIDJSON_NOEXCEPT_ASSERT(shared_->refcount > 0);
         size_t capacity = 0;
-        for (ChunkHeader* c = chunkHead_; c != 0; c = c->next)
+        for (ChunkHeader* c = shared_->chunkHead; c != 0; c = c->next)
             capacity += c->capacity;
         return capacity;
     }
@@ -178,25 +300,35 @@ public:
     //! Computes the memory blocks allocated.
     /*! \return total used bytes.
     */
-    size_t Size() const {
+    size_t Size() const RAPIDJSON_NOEXCEPT {
+        RAPIDJSON_NOEXCEPT_ASSERT(shared_->refcount > 0);
         size_t size = 0;
-        for (ChunkHeader* c = chunkHead_; c != 0; c = c->next)
+        for (ChunkHeader* c = shared_->chunkHead; c != 0; c = c->next)
             size += c->size;
         return size;
     }
 
+    //! Whether the allocator is shared.
+    /*! \return true or false.
+    */
+    bool Shared() const RAPIDJSON_NOEXCEPT {
+        RAPIDJSON_NOEXCEPT_ASSERT(shared_->refcount > 0);
+        return shared_->refcount > 1;
+    }
+
     //! Allocates a memory block. (concept Allocator)
     void* Malloc(size_t size) {
+        RAPIDJSON_NOEXCEPT_ASSERT(shared_->refcount > 0);
         if (!size)
             return NULL;
 
         size = RAPIDJSON_ALIGN(size);
-        if (chunkHead_ == 0 || chunkHead_->size + size > chunkHead_->capacity)
+        if (RAPIDJSON_UNLIKELY(shared_->chunkHead->size + size > shared_->chunkHead->capacity))
             if (!AddChunk(chunk_capacity_ > size ? chunk_capacity_ : size))
                 return NULL;
 
-        void *buffer = reinterpret_cast<char *>(chunkHead_) + RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + chunkHead_->size;
-        chunkHead_->size += size;
+        void *buffer = GetChunkBuffer(shared_) + shared_->chunkHead->size;
+        shared_->chunkHead->size += size;
         return buffer;
     }
 
@@ -205,6 +337,7 @@ public:
         if (originalPtr == 0)
             return Malloc(newSize);
 
+        RAPIDJSON_NOEXCEPT_ASSERT(shared_->refcount > 0);
         if (newSize == 0)
             return NULL;
 
@@ -216,10 +349,10 @@ public:
             return originalPtr;
 
         // Simply expand it if it is the last allocation and there is sufficient space
-        if (originalPtr == reinterpret_cast<char *>(chunkHead_) + RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + chunkHead_->size - originalSize) {
+        if (originalPtr == GetChunkBuffer(shared_) + shared_->chunkHead->size - originalSize) {
             size_t increment = static_cast<size_t>(newSize - originalSize);
-            if (chunkHead_->size + increment <= chunkHead_->capacity) {
-                chunkHead_->size += increment;
+            if (shared_->chunkHead->size + increment <= shared_->chunkHead->capacity) {
+                shared_->chunkHead->size += increment;
                 return originalPtr;
             }
         }
@@ -235,50 +368,325 @@ public:
     }
 
     //! Frees a memory block (concept Allocator)
-    static void Free(void *ptr) { (void)ptr; } // Do nothing
+    static void Free(void *ptr) RAPIDJSON_NOEXCEPT { (void)ptr; } // Do nothing
 
-private:
-    //! Copy constructor is not permitted.
-    MemoryPoolAllocator(const MemoryPoolAllocator& rhs) /* = delete */;
-    //! Copy assignment operator is not permitted.
-    MemoryPoolAllocator& operator=(const MemoryPoolAllocator& rhs) /* = delete */;
+    //! Compare (equality) with another MemoryPoolAllocator
+    bool operator==(const MemoryPoolAllocator& rhs) const RAPIDJSON_NOEXCEPT {
+        RAPIDJSON_NOEXCEPT_ASSERT(shared_->refcount > 0);
+        RAPIDJSON_NOEXCEPT_ASSERT(rhs.shared_->refcount > 0);
+        return shared_ == rhs.shared_;
+    }
+    //! Compare (inequality) with another MemoryPoolAllocator
+    bool operator!=(const MemoryPoolAllocator& rhs) const RAPIDJSON_NOEXCEPT {
+        return !operator==(rhs);
+    }
 
+private:
     //! Creates a new chunk.
     /*! \param capacity Capacity of the chunk in bytes.
         \return true if success.
     */
     bool AddChunk(size_t capacity) {
         if (!baseAllocator_)
-            ownBaseAllocator_ = baseAllocator_ = RAPIDJSON_NEW(BaseAllocator)();
-        if (ChunkHeader* chunk = reinterpret_cast<ChunkHeader*>(baseAllocator_->Malloc(RAPIDJSON_ALIGN(sizeof(ChunkHeader)) + capacity))) {
+            shared_->ownBaseAllocator = baseAllocator_ = RAPIDJSON_NEW(BaseAllocator)();
+        if (ChunkHeader* chunk = static_cast<ChunkHeader*>(baseAllocator_->Malloc(SIZEOF_CHUNK_HEADER + capacity))) {
             chunk->capacity = capacity;
             chunk->size = 0;
-            chunk->next = chunkHead_;
-            chunkHead_ =  chunk;
+            chunk->next = shared_->chunkHead;
+            shared_->chunkHead = chunk;
             return true;
         }
         else
             return false;
     }
 
-    static const int kDefaultChunkCapacity = RAPIDJSON_ALLOCATOR_DEFAULT_CHUNK_CAPACITY; //!< Default chunk capacity.
-
-    //! Chunk header for perpending to each chunk.
-    /*! Chunks are stored as a singly linked list.
-    */
-    struct ChunkHeader {
-        size_t capacity;    //!< Capacity of the chunk in bytes (excluding the header itself).
-        size_t size;        //!< Current size of allocated memory in bytes.
-        ChunkHeader *next;  //!< Next chunk in the linked list.
-    };
+    static inline void* AlignBuffer(void* buf, size_t &size)
+    {
+        RAPIDJSON_NOEXCEPT_ASSERT(buf != 0);
+        const uintptr_t mask = sizeof(void*) - 1;
+        const uintptr_t ubuf = reinterpret_cast<uintptr_t>(buf);
+        if (RAPIDJSON_UNLIKELY(ubuf & mask)) {
+            const uintptr_t abuf = (ubuf + mask) & ~mask;
+            RAPIDJSON_ASSERT(size >= abuf - ubuf);
+            buf = reinterpret_cast<void*>(abuf);
+            size -= abuf - ubuf;
+        }
+        return buf;
+    }
 
-    ChunkHeader *chunkHead_;    //!< Head of the chunk linked-list. Only the head chunk serves allocation.
     size_t chunk_capacity_;     //!< The minimum capacity of chunk when they are allocated.
-    void *userBuffer_;          //!< User supplied buffer.
     BaseAllocator* baseAllocator_;  //!< base allocator for allocating memory chunks.
-    BaseAllocator* ownBaseAllocator_;   //!< base allocator created by this object.
+    SharedData *shared_;        //!< The shared data of the allocator
 };
 
+namespace internal {
+    template<typename, typename = void>
+    struct IsRefCounted :
+        public FalseType
+    { };
+    template<typename T>
+    struct IsRefCounted<T, typename internal::EnableIfCond<T::kRefCounted>::Type> :
+        public TrueType
+    { };
+}
+
+template<typename T, typename A>
+inline T* Realloc(A& a, T* old_p, size_t old_n, size_t new_n)
+{
+    RAPIDJSON_NOEXCEPT_ASSERT(old_n <= SIZE_MAX / sizeof(T) && new_n <= SIZE_MAX / sizeof(T));
+    return static_cast<T*>(a.Realloc(old_p, old_n * sizeof(T), new_n * sizeof(T)));
+}
+
+template<typename T, typename A>
+inline T *Malloc(A& a, size_t n = 1)
+{
+    return Realloc<T, A>(a, NULL, 0, n);
+}
+
+template<typename T, typename A>
+inline void Free(A& a, T *p, size_t n = 1)
+{
+    static_cast<void>(Realloc<T, A>(a, p, n, 0));
+}
+
+#ifdef __GNUC__
+RAPIDJSON_DIAG_PUSH
+RAPIDJSON_DIAG_OFF(effc++) // std::allocator can safely be inherited
+#endif
+
+template <typename T, typename BaseAllocator = CrtAllocator>
+class StdAllocator :
+    public std::allocator<T>
+{
+    typedef std::allocator<T> allocator_type;
+#if RAPIDJSON_HAS_CXX11
+    typedef std::allocator_traits<allocator_type> traits_type;
+#else
+    typedef allocator_type traits_type;
+#endif
+
+public:
+    typedef BaseAllocator BaseAllocatorType;
+
+    StdAllocator() RAPIDJSON_NOEXCEPT :
+        allocator_type(),
+        baseAllocator_()
+    { }
+
+    StdAllocator(const StdAllocator& rhs) RAPIDJSON_NOEXCEPT :
+        allocator_type(rhs),
+        baseAllocator_(rhs.baseAllocator_)
+    { }
+
+    template<typename U>
+    StdAllocator(const StdAllocator<U, BaseAllocator>& rhs) RAPIDJSON_NOEXCEPT :
+        allocator_type(rhs),
+        baseAllocator_(rhs.baseAllocator_)
+    { }
+
+#if RAPIDJSON_HAS_CXX11_RVALUE_REFS
+    StdAllocator(StdAllocator&& rhs) RAPIDJSON_NOEXCEPT :
+        allocator_type(std::move(rhs)),
+        baseAllocator_(std::move(rhs.baseAllocator_))
+    { }
+#endif
+#if RAPIDJSON_HAS_CXX11
+    using propagate_on_container_move_assignment = std::true_type;
+    using propagate_on_container_swap = std::true_type;
+#endif
+
+    /* implicit */
+    StdAllocator(const BaseAllocator& allocator) RAPIDJSON_NOEXCEPT :
+        allocator_type(),
+        baseAllocator_(allocator)
+    { }
+
+    ~StdAllocator() RAPIDJSON_NOEXCEPT
+    { }
+
+    template<typename U>
+    struct rebind {
+        typedef StdAllocator<U, BaseAllocator> other;
+    };
+
+    typedef typename traits_type::size_type         size_type;
+    typedef typename traits_type::difference_type   difference_type;
+
+    typedef typename traits_type::value_type        value_type;
+    typedef typename traits_type::pointer           pointer;
+    typedef typename traits_type::const_pointer     const_pointer;
+
+#if RAPIDJSON_HAS_CXX11
+
+    typedef typename std::add_lvalue_reference<value_type>::type &reference;
+    typedef typename std::add_lvalue_reference<typename std::add_const<value_type>::type>::type &const_reference;
+
+    pointer address(reference r) const RAPIDJSON_NOEXCEPT
+    {
+        return std::addressof(r);
+    }
+    const_pointer address(const_reference r) const RAPIDJSON_NOEXCEPT
+    {
+        return std::addressof(r);
+    }
+
+    size_type max_size() const RAPIDJSON_NOEXCEPT
+    {
+        return traits_type::max_size(*this);
+    }
+
+    template <typename ...Args>
+    void construct(pointer p, Args&&... args)
+    {
+        traits_type::construct(*this, p, std::forward<Args>(args)...);
+    }
+    void destroy(pointer p)
+    {
+        traits_type::destroy(*this, p);
+    }
+
+#else // !RAPIDJSON_HAS_CXX11
+
+    typedef typename allocator_type::reference       reference;
+    typedef typename allocator_type::const_reference const_reference;
+
+    pointer address(reference r) const RAPIDJSON_NOEXCEPT
+    {
+        return allocator_type::address(r);
+    }
+    const_pointer address(const_reference r) const RAPIDJSON_NOEXCEPT
+    {
+        return allocator_type::address(r);
+    }
+
+    size_type max_size() const RAPIDJSON_NOEXCEPT
+    {
+        return allocator_type::max_size();
+    }
+
+    void construct(pointer p, const_reference r)
+    {
+        allocator_type::construct(p, r);
+    }
+    void destroy(pointer p)
+    {
+        allocator_type::destroy(p);
+    }
+
+#endif // !RAPIDJSON_HAS_CXX11
+
+    template <typename U>
+    U* allocate(size_type n = 1, const void* = 0)
+    {
+        return RAPIDJSON_NAMESPACE::Malloc<U>(baseAllocator_, n);
+    }
+    template <typename U>
+    void deallocate(U* p, size_type n = 1)
+    {
+        RAPIDJSON_NAMESPACE::Free<U>(baseAllocator_, p, n);
+    }
+
+    pointer allocate(size_type n = 1, const void* = 0)
+    {
+        return allocate<value_type>(n);
+    }
+    void deallocate(pointer p, size_type n = 1)
+    {
+        deallocate<value_type>(p, n);
+    }
+
+#if RAPIDJSON_HAS_CXX11
+    using is_always_equal = std::is_empty<BaseAllocator>;
+#endif
+
+    template<typename U>
+    bool operator==(const StdAllocator<U, BaseAllocator>& rhs) const RAPIDJSON_NOEXCEPT
+    {
+        return baseAllocator_ == rhs.baseAllocator_;
+    }
+    template<typename U>
+    bool operator!=(const StdAllocator<U, BaseAllocator>& rhs) const RAPIDJSON_NOEXCEPT
+    {
+        return !operator==(rhs);
+    }
+
+    //! rapidjson Allocator concept
+    static const bool kNeedFree = BaseAllocator::kNeedFree;
+    static const bool kRefCounted = internal::IsRefCounted<BaseAllocator>::Value;
+    void* Malloc(size_t size)
+    {
+        return baseAllocator_.Malloc(size);
+    }
+    void* Realloc(void* originalPtr, size_t originalSize, size_t newSize)
+    {
+        return baseAllocator_.Realloc(originalPtr, originalSize, newSize);
+    }
+    static void Free(void *ptr) RAPIDJSON_NOEXCEPT
+    {
+        BaseAllocator::Free(ptr);
+    }
+
+private:
+    template <typename, typename>
+    friend class StdAllocator; // access to StdAllocator<!T>.*
+
+    BaseAllocator baseAllocator_;
+};
+
+#if !RAPIDJSON_HAS_CXX17 // std::allocator<void> deprecated in C++17
+template <typename BaseAllocator>
+class StdAllocator<void, BaseAllocator> :
+    public std::allocator<void>
+{
+    typedef std::allocator<void> allocator_type;
+
+public:
+    typedef BaseAllocator BaseAllocatorType;
+
+    StdAllocator() RAPIDJSON_NOEXCEPT :
+        allocator_type(),
+        baseAllocator_()
+    { }
+
+    StdAllocator(const StdAllocator& rhs) RAPIDJSON_NOEXCEPT :
+        allocator_type(rhs),
+        baseAllocator_(rhs.baseAllocator_)
+    { }
+
+    template<typename U>
+    StdAllocator(const StdAllocator<U, BaseAllocator>& rhs) RAPIDJSON_NOEXCEPT :
+        allocator_type(rhs),
+        baseAllocator_(rhs.baseAllocator_)
+    { }
+
+    /* implicit */
+    StdAllocator(const BaseAllocator& baseAllocator) RAPIDJSON_NOEXCEPT :
+        allocator_type(),
+        baseAllocator_(baseAllocator)
+    { }
+
+    ~StdAllocator() RAPIDJSON_NOEXCEPT
+    { }
+
+    template<typename U>
+    struct rebind {
+        typedef StdAllocator<U, BaseAllocator> other;
+    };
+
+    typedef typename allocator_type::value_type value_type;
+
+private:
+    template <typename, typename>
+    friend class StdAllocator; // access to StdAllocator<!T>.*
+
+    BaseAllocator baseAllocator_;
+};
+#endif
+
+#ifdef __GNUC__
+RAPIDJSON_DIAG_POP
+#endif
+
 RAPIDJSON_NAMESPACE_END
 
 #endif // RAPIDJSON_ENCODINGS_H_
diff --git a/include/rapidjson/document.h b/include/rapidjson/document.h
index 1dad630e..e2cc6000 100644
--- a/include/rapidjson/document.h
+++ b/include/rapidjson/document.h
@@ -42,12 +42,21 @@ RAPIDJSON_DIAG_OFF(4244) // conversion from kXxxFlags to 'uint16_t', possible lo
 RAPIDJSON_DIAG_OFF(effc++)
 #endif // __GNUC__
 
+#ifdef GetObject
+// see https://github.com/Tencent/rapidjson/issues/1448
+// a former included windows.h might have defined a macro called GetObject, which affects
+// GetObject defined here. This ensures the macro does not get applied
+#pragma push_macro("GetObject")
+#define RAPIDJSON_WINDOWS_GETOBJECT_WORKAROUND_APPLIED
+#undef GetObject
+#endif
+
 #ifndef RAPIDJSON_NOMEMBERITERATORCLASS
 #include <iterator> // std::random_access_iterator_tag
 #endif
 
-#if RAPIDJSON_HAS_CXX11_RVALUE_REFS
-#include <utility> // std::move
+#if RAPIDJSON_USE_MEMBERSMAP
+#include <map> // std::multimap
 #endif
 
 RAPIDJSON_NAMESPACE_BEGIN
@@ -732,18 +741,8 @@ public:
     template <typename SourceAllocator>
     GenericValue(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator& allocator, bool copyConstStrings = false) {
         switch (rhs.GetType()) {
-        case kObjectType: {
-                SizeType count = rhs.data_.o.size;
-                Member* lm = reinterpret_cast<Member*>(allocator.Malloc(count * sizeof(Member)));
-                const typename GenericValue<Encoding,SourceAllocator>::Member* rm = rhs.GetMembersPointer();
-                for (SizeType i = 0; i < count; i++) {
-                    new (&lm[i].name) GenericValue(rm[i].name, allocator, copyConstStrings);
-                    new (&lm[i].value) GenericValue(rm[i].value, allocator, copyConstStrings);
-                }
-                data_.f.flags = kObjectFlag;
-                data_.o.size = data_.o.capacity = count;
-                SetMembersPointer(lm);
-            }
+        case kObjectType:
+            DoCopyMembers(rhs, allocator, copyConstStrings);
             break;
         case kArrayType: {
                 SizeType count = rhs.data_.a.size;
@@ -879,25 +878,30 @@ public:
     /*! Need to destruct elements of array, members of object, or copy-string.
     */
     ~GenericValue() {
-        if (Allocator::kNeedFree) { // Shortcut by Allocator's trait
+        // With RAPIDJSON_USE_MEMBERSMAP, the maps need to be destroyed to release
+        // their Allocator if it's refcounted (e.g. MemoryPoolAllocator).
+        if (Allocator::kNeedFree || (RAPIDJSON_USE_MEMBERSMAP+0 &&
+                                     internal::IsRefCounted<Allocator>::Value)) {
             switch(data_.f.flags) {
             case kArrayFlag:
                 {
                     GenericValue* e = GetElementsPointer();
                     for (GenericValue* v = e; v != e + data_.a.size; ++v)
                         v->~GenericValue();
-                    Allocator::Free(e);
+                    if (Allocator::kNeedFree) { // Shortcut by Allocator's trait
+                        Allocator::Free(e);
+                    }
                 }
                 break;
 
             case kObjectFlag:
-                for (MemberIterator m = MemberBegin(); m != MemberEnd(); ++m)
-                    m->~Member();
-                Allocator::Free(GetMembersPointer());
+                DoFreeMembers();
                 break;
 
             case kCopyStringFlag:
-                Allocator::Free(const_cast<Ch*>(GetStringPointer()));
+                if (Allocator::kNeedFree) { // Shortcut by Allocator's trait
+                    Allocator::Free(const_cast<Ch*>(GetStringPointer()));
+                }
                 break;
 
             default:
@@ -916,8 +920,13 @@ public:
     */
     GenericValue& operator=(GenericValue& rhs) RAPIDJSON_NOEXCEPT {
         if (RAPIDJSON_LIKELY(this != &rhs)) {
+            // Can't destroy "this" before assigning "rhs", otherwise "rhs"
+            // could be used after free if it's an sub-Value of "this",
+            // hence the temporary danse.
+            GenericValue temp;
+            temp.RawAssign(rhs);
             this->~GenericValue();
-            RawAssign(rhs);
+            RawAssign(temp);
         }
         return *this;
     }
@@ -1260,10 +1269,7 @@ public:
     */
     GenericValue& MemberReserve(SizeType newCapacity, Allocator &allocator) {
         RAPIDJSON_ASSERT(IsObject());
-        if (newCapacity > data_.o.capacity) {
-            SetMembersPointer(reinterpret_cast<Member*>(allocator.Realloc(GetMembersPointer(), data_.o.capacity * sizeof(Member), newCapacity * sizeof(Member))));
-            data_.o.capacity = newCapacity;
-        }
+        DoReserveMembers(newCapacity, allocator);
         return *this;
     }
 
@@ -1337,11 +1343,7 @@ public:
     MemberIterator FindMember(const GenericValue<Encoding, SourceAllocator>& name) {
         RAPIDJSON_ASSERT(IsObject());
         RAPIDJSON_ASSERT(name.IsString());
-        MemberIterator member = MemberBegin();
-        for ( ; member != MemberEnd(); ++member)
-            if (name.StringEqual(member->name))
-                break;
-        return member;
+        return DoFindMember(name);
     }
     template <typename SourceAllocator> ConstMemberIterator FindMember(const GenericValue<Encoding, SourceAllocator>& name) const { return const_cast<GenericValue&>(*this).FindMember(name); }
 
@@ -1370,14 +1372,7 @@ public:
     GenericValue& AddMember(GenericValue& name, GenericValue& value, Allocator& allocator) {
         RAPIDJSON_ASSERT(IsObject());
         RAPIDJSON_ASSERT(name.IsString());
-
-        ObjectData& o = data_.o;
-        if (o.size >= o.capacity)
-            MemberReserve(o.capacity == 0 ? kDefaultObjectCapacity : (o.capacity + (o.capacity + 1) / 2), allocator);
-        Member* members = GetMembersPointer();
-        members[o.size].name.RawAssign(name);
-        members[o.size].value.RawAssign(value);
-        o.size++;
+        DoAddMember(name, value, allocator);
         return *this;
     }
 
@@ -1511,9 +1506,7 @@ public:
     */
     void RemoveAllMembers() {
         RAPIDJSON_ASSERT(IsObject()); 
-        for (MemberIterator m = MemberBegin(); m != MemberEnd(); ++m)
-            m->~Member();
-        data_.o.size = 0;
+        DoClearMembers();
     }
 
     //! Remove a member in object by its name.
@@ -1557,14 +1550,7 @@ public:
         RAPIDJSON_ASSERT(data_.o.size > 0);
         RAPIDJSON_ASSERT(GetMembersPointer() != 0);
         RAPIDJSON_ASSERT(m >= MemberBegin() && m < MemberEnd());
-
-        MemberIterator last(GetMembersPointer() + (data_.o.size - 1));
-        if (data_.o.size > 1 && m != last)
-            *m = *last; // Move the last one to this place
-        else
-            m->~Member(); // Only one left, just destroy
-        --data_.o.size;
-        return m;
+        return DoRemoveMember(m);
     }
 
     //! Remove a member from an object by iterator.
@@ -1596,13 +1582,7 @@ public:
         RAPIDJSON_ASSERT(first >= MemberBegin());
         RAPIDJSON_ASSERT(first <= last);
         RAPIDJSON_ASSERT(last <= MemberEnd());
-
-        MemberIterator pos = MemberBegin() + (first - MemberBegin());
-        for (MemberIterator itr = pos; itr != last; ++itr)
-            itr->~Member();
-        std::memmove(static_cast<void*>(&*pos), &*last, static_cast<size_t>(MemberEnd() - last) * sizeof(Member));
-        data_.o.size -= static_cast<SizeType>(last - first);
-        return pos;
+        return DoEraseMembers(first, last);
     }
 
     //! Erase a member in object by its name.
@@ -1631,7 +1611,9 @@ public:
     }
 
     Object GetObject() { RAPIDJSON_ASSERT(IsObject()); return Object(*this); }
+    Object GetObj() { RAPIDJSON_ASSERT(IsObject()); return Object(*this); }
     ConstObject GetObject() const { RAPIDJSON_ASSERT(IsObject()); return ConstObject(*this); }
+    ConstObject GetObj() const { RAPIDJSON_ASSERT(IsObject()); return ConstObject(*this); }
 
     //@}
 
@@ -1853,12 +1835,12 @@ public:
     //!@name String
     //@{
 
-    const Ch* GetString() const { RAPIDJSON_ASSERT(IsString()); return (data_.f.flags & kInlineStrFlag) ? data_.ss.str : GetStringPointer(); }
+    const Ch* GetString() const { RAPIDJSON_ASSERT(IsString()); return DataString(data_); }
 
     //! Get the length of string.
     /*! Since rapidjson permits "\\u0000" in the json string, strlen(v.GetString()) may not equal to v.GetStringLength().
     */
-    SizeType GetStringLength() const { RAPIDJSON_ASSERT(IsString()); return ((data_.f.flags & kInlineStrFlag) ? (data_.ss.GetLength()) : data_.s.length); }
+    SizeType GetStringLength() const { RAPIDJSON_ASSERT(IsString()); return DataStringLength(data_); }
 
     //! Set this value as a string without copying source string.
     /*! This version has better performance with supplied length, and also support string containing null character.
@@ -2107,6 +2089,13 @@ private:
         Flag f;
     };  // 16 bytes in 32-bit mode, 24 bytes in 64-bit mode, 16 bytes in 64-bit with RAPIDJSON_48BITPOINTER_OPTIMIZATION
 
+    static RAPIDJSON_FORCEINLINE const Ch* DataString(const Data& data) {
+        return (data.f.flags & kInlineStrFlag) ? data.ss.str : RAPIDJSON_GETPOINTER(Ch, data.s.str);
+    }
+    static RAPIDJSON_FORCEINLINE SizeType DataStringLength(const Data& data) {
+        return (data.f.flags & kInlineStrFlag) ? data.ss.GetLength() : data.s.length;
+    }
+
     RAPIDJSON_FORCEINLINE const Ch* GetStringPointer() const { return RAPIDJSON_GETPOINTER(Ch, data_.s.str); }
     RAPIDJSON_FORCEINLINE const Ch* SetStringPointer(const Ch* str) { return RAPIDJSON_SETPOINTER(Ch, data_.s.str, str); }
     RAPIDJSON_FORCEINLINE GenericValue* GetElementsPointer() const { return RAPIDJSON_GETPOINTER(GenericValue, data_.a.elements); }
@@ -2114,6 +2103,286 @@ private:
     RAPIDJSON_FORCEINLINE Member* GetMembersPointer() const { return RAPIDJSON_GETPOINTER(Member, data_.o.members); }
     RAPIDJSON_FORCEINLINE Member* SetMembersPointer(Member* members) { return RAPIDJSON_SETPOINTER(Member, data_.o.members, members); }
 
+#if RAPIDJSON_USE_MEMBERSMAP
+
+    struct MapTraits {
+        struct Less {
+            bool operator()(const Data& s1, const Data& s2) const {
+                SizeType n1 = DataStringLength(s1), n2 = DataStringLength(s2);
+                int cmp = std::memcmp(DataString(s1), DataString(s2), sizeof(Ch) * (n1 < n2 ? n1 : n2));
+                return cmp < 0 || (cmp == 0 && n1 < n2);
+            }
+        };
+        typedef std::pair<const Data, SizeType> Pair;
+        typedef std::multimap<Data, SizeType, Less, StdAllocator<Pair, Allocator> > Map;
+        typedef typename Map::iterator Iterator;
+    };
+    typedef typename MapTraits::Map         Map;
+    typedef typename MapTraits::Less        MapLess;
+    typedef typename MapTraits::Pair        MapPair;
+    typedef typename MapTraits::Iterator    MapIterator;
+
+    //
+    // Layout of the members' map/array, re(al)located according to the needed capacity:
+    //
+    //    {Map*}<>{capacity}<>{Member[capacity]}<>{MapIterator[capacity]}
+    //
+    // (where <> stands for the RAPIDJSON_ALIGN-ment, if needed)
+    //
+
+    static RAPIDJSON_FORCEINLINE size_t GetMapLayoutSize(SizeType capacity) {
+        return RAPIDJSON_ALIGN(sizeof(Map*)) +
+               RAPIDJSON_ALIGN(sizeof(SizeType)) +
+               RAPIDJSON_ALIGN(capacity * sizeof(Member)) +
+               capacity * sizeof(MapIterator);
+    }
+
+    static RAPIDJSON_FORCEINLINE SizeType &GetMapCapacity(Map* &map) {
+        return *reinterpret_cast<SizeType*>(reinterpret_cast<uintptr_t>(&map) +
+                                            RAPIDJSON_ALIGN(sizeof(Map*)));
+    }
+
+    static RAPIDJSON_FORCEINLINE Member* GetMapMembers(Map* &map) {
+        return reinterpret_cast<Member*>(reinterpret_cast<uintptr_t>(&map) +
+                                         RAPIDJSON_ALIGN(sizeof(Map*)) +
+                                         RAPIDJSON_ALIGN(sizeof(SizeType)));
+    }
+
+    static RAPIDJSON_FORCEINLINE MapIterator* GetMapIterators(Map* &map) {
+        return reinterpret_cast<MapIterator*>(reinterpret_cast<uintptr_t>(&map) +
+                                              RAPIDJSON_ALIGN(sizeof(Map*)) +
+                                              RAPIDJSON_ALIGN(sizeof(SizeType)) +
+                                              RAPIDJSON_ALIGN(GetMapCapacity(map) * sizeof(Member)));
+    }
+
+    static RAPIDJSON_FORCEINLINE Map* &GetMap(Member* members) {
+        RAPIDJSON_ASSERT(members != 0);
+        return *reinterpret_cast<Map**>(reinterpret_cast<uintptr_t>(members) -
+                                        RAPIDJSON_ALIGN(sizeof(SizeType)) -
+                                        RAPIDJSON_ALIGN(sizeof(Map*)));
+    }
+
+    // Some compilers' debug mechanisms want all iterators to be destroyed, for their accounting..
+    RAPIDJSON_FORCEINLINE MapIterator DropMapIterator(MapIterator& rhs) {
+#if RAPIDJSON_HAS_CXX11
+        MapIterator ret = std::move(rhs);
+#else
+        MapIterator ret = rhs;
+#endif
+        rhs.~MapIterator();
+        return ret;
+    }
+
+    Map* &DoReallocMap(Map** oldMap, SizeType newCapacity, Allocator& allocator) {
+        Map **newMap = static_cast<Map**>(allocator.Malloc(GetMapLayoutSize(newCapacity)));
+        GetMapCapacity(*newMap) = newCapacity;
+        if (!oldMap) {
+            *newMap = new (allocator.Malloc(sizeof(Map))) Map(MapLess(), allocator);
+        }
+        else {
+            *newMap = *oldMap;
+            size_t count = (*oldMap)->size();
+            std::memcpy(static_cast<void*>(GetMapMembers(*newMap)),
+                        static_cast<void*>(GetMapMembers(*oldMap)),
+                        count * sizeof(Member));
+            MapIterator *oldIt = GetMapIterators(*oldMap),
+                        *newIt = GetMapIterators(*newMap);
+            while (count--) {
+                new (&newIt[count]) MapIterator(DropMapIterator(oldIt[count]));
+            }
+            Allocator::Free(oldMap);
+        }
+        return *newMap;
+    }
+
+    RAPIDJSON_FORCEINLINE Member* DoAllocMembers(SizeType capacity, Allocator& allocator) {
+        return GetMapMembers(DoReallocMap(0, capacity, allocator));
+    }
+
+    void DoReserveMembers(SizeType newCapacity, Allocator& allocator) {
+        ObjectData& o = data_.o;
+        if (newCapacity > o.capacity) {
+            Member* oldMembers = GetMembersPointer();
+            Map **oldMap = oldMembers ? &GetMap(oldMembers) : 0,
+                *&newMap = DoReallocMap(oldMap, newCapacity, allocator);
+            RAPIDJSON_SETPOINTER(Member, o.members, GetMapMembers(newMap));
+            o.capacity = newCapacity;
+        }
+    }
+
+    template <typename SourceAllocator>
+    MemberIterator DoFindMember(const GenericValue<Encoding, SourceAllocator>& name) {
+        if (Member* members = GetMembersPointer()) {
+            Map* &map = GetMap(members);
+            MapIterator mit = map->find(reinterpret_cast<const Data&>(name.data_));
+            if (mit != map->end()) {
+                return MemberIterator(&members[mit->second]);
+            }
+        }
+        return MemberEnd();
+    }
+
+    void DoClearMembers() {
+        if (Member* members = GetMembersPointer()) {
+            Map* &map = GetMap(members);
+            MapIterator* mit = GetMapIterators(map);
+            for (SizeType i = 0; i < data_.o.size; i++) {
+                map->erase(DropMapIterator(mit[i]));
+                members[i].~Member();
+            }
+            data_.o.size = 0;
+        }
+    }
+
+    void DoFreeMembers() {
+        if (Member* members = GetMembersPointer()) {
+            GetMap(members)->~Map();
+            for (SizeType i = 0; i < data_.o.size; i++) {
+                members[i].~Member();
+            }
+            if (Allocator::kNeedFree) { // Shortcut by Allocator's trait
+                Map** map = &GetMap(members);
+                Allocator::Free(*map);
+                Allocator::Free(map);
+            }
+        }
+    }
+
+#else // !RAPIDJSON_USE_MEMBERSMAP
+
+    RAPIDJSON_FORCEINLINE Member* DoAllocMembers(SizeType capacity, Allocator& allocator) {
+        return Malloc<Member>(allocator, capacity);
+    }
+
+    void DoReserveMembers(SizeType newCapacity, Allocator& allocator) {
+        ObjectData& o = data_.o;
+        if (newCapacity > o.capacity) {
+            Member* newMembers = Realloc<Member>(allocator, GetMembersPointer(), o.capacity, newCapacity);
+            RAPIDJSON_SETPOINTER(Member, o.members, newMembers);
+            o.capacity = newCapacity;
+        }
+    }
+
+    template <typename SourceAllocator>
+    MemberIterator DoFindMember(const GenericValue<Encoding, SourceAllocator>& name) {
+        MemberIterator member = MemberBegin();
+        for ( ; member != MemberEnd(); ++member)
+            if (name.StringEqual(member->name))
+                break;
+        return member;
+    }
+
+    void DoClearMembers() {
+        for (MemberIterator m = MemberBegin(); m != MemberEnd(); ++m)
+            m->~Member();
+        data_.o.size = 0;
+    }
+
+    void DoFreeMembers() {
+        for (MemberIterator m = MemberBegin(); m != MemberEnd(); ++m)
+            m->~Member();
+        Allocator::Free(GetMembersPointer());
+    }
+
+#endif // !RAPIDJSON_USE_MEMBERSMAP
+
+    void DoAddMember(GenericValue& name, GenericValue& value, Allocator& allocator) {
+        ObjectData& o = data_.o;
+        if (o.size >= o.capacity)
+            DoReserveMembers(o.capacity ? (o.capacity + (o.capacity + 1) / 2) : kDefaultObjectCapacity, allocator);
+        Member* members = GetMembersPointer();
+        Member* m = members + o.size;
+        m->name.RawAssign(name);
+        m->value.RawAssign(value);
+#if RAPIDJSON_USE_MEMBERSMAP
+        Map* &map = GetMap(members);
+        MapIterator* mit = GetMapIterators(map);
+        new (&mit[o.size]) MapIterator(map->insert(MapPair(m->name.data_, o.size)));
+#endif
+        ++o.size;
+    }
+
+    MemberIterator DoRemoveMember(MemberIterator m) {
+        ObjectData& o = data_.o;
+        Member* members = GetMembersPointer();
+#if RAPIDJSON_USE_MEMBERSMAP
+        Map* &map = GetMap(members);
+        MapIterator* mit = GetMapIterators(map);
+        SizeType mpos = static_cast<SizeType>(&*m - members);
+        map->erase(DropMapIterator(mit[mpos]));
+#endif
+        MemberIterator last(members + (o.size - 1));
+        if (o.size > 1 && m != last) {
+#if RAPIDJSON_USE_MEMBERSMAP
+            new (&mit[mpos]) MapIterator(DropMapIterator(mit[&*last - members]));
+            mit[mpos]->second = mpos;
+#endif
+            *m = *last; // Move the last one to this place
+        }
+        else {
+            m->~Member(); // Only one left, just destroy
+        }
+        --o.size;
+        return m;
+    }
+
+    MemberIterator DoEraseMembers(ConstMemberIterator first, ConstMemberIterator last) {
+        ObjectData& o = data_.o;
+        MemberIterator beg = MemberBegin(),
+                       pos = beg + (first - beg),
+                       end = MemberEnd();
+#if RAPIDJSON_USE_MEMBERSMAP
+        Map* &map = GetMap(GetMembersPointer());
+        MapIterator* mit = GetMapIterators(map);
+#endif
+        for (MemberIterator itr = pos; itr != last; ++itr) {
+#if RAPIDJSON_USE_MEMBERSMAP
+            map->erase(DropMapIterator(mit[itr - beg]));
+#endif
+            itr->~Member();
+        }
+#if RAPIDJSON_USE_MEMBERSMAP
+        if (first != last) {
+            // Move remaining members/iterators
+            MemberIterator next = pos + (last - first);
+            for (MemberIterator itr = pos; next != end; ++itr, ++next) {
+                std::memcpy(static_cast<void*>(&*itr), &*next, sizeof(Member));
+                SizeType mpos = static_cast<SizeType>(itr - beg);
+                new (&mit[mpos]) MapIterator(DropMapIterator(mit[next - beg]));
+                mit[mpos]->second = mpos;
+            }
+        }
+#else
+        std::memmove(static_cast<void*>(&*pos), &*last,
+                     static_cast<size_t>(end - last) * sizeof(Member));
+#endif
+        o.size -= static_cast<SizeType>(last - first);
+        return pos;
+    }
+
+    template <typename SourceAllocator>
+    void DoCopyMembers(const GenericValue<Encoding,SourceAllocator>& rhs, Allocator& allocator, bool copyConstStrings) {
+        RAPIDJSON_ASSERT(rhs.GetType() == kObjectType);
+
+        data_.f.flags = kObjectFlag;
+        SizeType count = rhs.data_.o.size;
+        Member* lm = DoAllocMembers(count, allocator);
+        const typename GenericValue<Encoding,SourceAllocator>::Member* rm = rhs.GetMembersPointer();
+#if RAPIDJSON_USE_MEMBERSMAP
+        Map* &map = GetMap(lm);
+        MapIterator* mit = GetMapIterators(map);
+#endif
+        for (SizeType i = 0; i < count; i++) {
+            new (&lm[i].name) GenericValue(rm[i].name, allocator, copyConstStrings);
+            new (&lm[i].value) GenericValue(rm[i].value, allocator, copyConstStrings);
+#if RAPIDJSON_USE_MEMBERSMAP
+            new (&mit[i]) MapIterator(map->insert(MapPair(lm[i].name.data_, i)));
+#endif
+        }
+        data_.o.size = data_.o.capacity = count;
+        SetMembersPointer(lm);
+    }
+
     // Initialize this value as array with initial data, without calling destructor.
     void SetArrayRaw(GenericValue* values, SizeType count, Allocator& allocator) {
         data_.f.flags = kArrayFlag;
@@ -2131,9 +2400,16 @@ private:
     void SetObjectRaw(Member* members, SizeType count, Allocator& allocator) {
         data_.f.flags = kObjectFlag;
         if (count) {
-            Member* m = static_cast<Member*>(allocator.Malloc(count * sizeof(Member)));
+            Member* m = DoAllocMembers(count, allocator);
             SetMembersPointer(m);
             std::memcpy(static_cast<void*>(m), members, count * sizeof(Member));
+#if RAPIDJSON_USE_MEMBERSMAP
+            Map* &map = GetMap(m);
+            MapIterator* mit = GetMapIterators(map);
+            for (SizeType i = 0; i < count; i++) {
+                new (&mit[i]) MapIterator(map->insert(MapPair(m[i].name.data_, i)));
+            }
+#endif
         }
         else
             SetMembersPointer(0);
@@ -2254,6 +2530,13 @@ public:
 #endif
 
     ~GenericDocument() {
+        // Clear the ::ValueType before ownAllocator is destroyed, ~ValueType()
+        // runs last and may access its elements or members which would be freed
+        // with an allocator like MemoryPoolAllocator (CrtAllocator does not
+        // free its data when destroyed, but MemoryPoolAllocator does).
+        if (ownAllocator_) {
+            ValueType::SetNull();
+        }
         Destroy();
     }
 
@@ -2736,4 +3019,9 @@ private:
 RAPIDJSON_NAMESPACE_END
 RAPIDJSON_DIAG_POP
 
+#ifdef RAPIDJSON_WINDOWS_GETOBJECT_WORKAROUND_APPLIED
+#pragma pop_macro("GetObject")
+#undef RAPIDJSON_WINDOWS_GETOBJECT_WORKAROUND_APPLIED
+#endif
+
 #endif // RAPIDJSON_DOCUMENT_H_
diff --git a/include/rapidjson/rapidjson.h b/include/rapidjson/rapidjson.h
index 78aa89a0..a4e89532 100644
--- a/include/rapidjson/rapidjson.h
+++ b/include/rapidjson/rapidjson.h
@@ -125,6 +125,19 @@
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
+// __cplusplus macro
+
+//!@cond RAPIDJSON_HIDDEN_FROM_DOXYGEN
+
+#if defined(_MSC_VER)
+#define RAPIDJSON_CPLUSPLUS _MSVC_LANG
+#else
+#define RAPIDJSON_CPLUSPLUS __cplusplus
+#endif
+
+//!@endcond
+
+///////////////////////////////////////////////////////////////////////////////
 // RAPIDJSON_HAS_STDSTRING
 
 #ifndef RAPIDJSON_HAS_STDSTRING
@@ -150,6 +163,24 @@
 #endif // RAPIDJSON_HAS_STDSTRING
 
 ///////////////////////////////////////////////////////////////////////////////
+// RAPIDJSON_USE_MEMBERSMAP
+
+/*! \def RAPIDJSON_USE_MEMBERSMAP
+    \ingroup RAPIDJSON_CONFIG
+    \brief Enable RapidJSON support for object members handling in a \c std::multimap
+
+    By defining this preprocessor symbol to \c 1, \ref rapidjson::GenericValue object
+    members are stored in a \c std::multimap for faster lookup and deletion times, a
+    trade off with a slightly slower insertion time and a small object allocat(or)ed
+    memory overhead.
+
+    \hideinitializer
+*/
+#ifndef RAPIDJSON_USE_MEMBERSMAP
+#define RAPIDJSON_USE_MEMBERSMAP 0 // not by default
+#endif
+
+///////////////////////////////////////////////////////////////////////////////
 // RAPIDJSON_NO_INT64DEFINE
 
 /*! \def RAPIDJSON_NO_INT64DEFINE
@@ -411,7 +442,7 @@ RAPIDJSON_NAMESPACE_END
 
 // Prefer C++11 static_assert, if available
 #ifndef RAPIDJSON_STATIC_ASSERT
-#if __cplusplus >= 201103L || ( defined(_MSC_VER) && _MSC_VER >= 1800 )
+#if RAPIDJSON_CPLUSPLUS >= 201103L || ( defined(_MSC_VER) && _MSC_VER >= 1800 )
 #define RAPIDJSON_STATIC_ASSERT(x) \
    static_assert(x, RAPIDJSON_STRINGIFY(x))
 #endif // C++11
@@ -541,8 +572,14 @@ RAPIDJSON_NAMESPACE_END
 ///////////////////////////////////////////////////////////////////////////////
 // C++11 features
 
+#ifndef RAPIDJSON_HAS_CXX11
+#define RAPIDJSON_HAS_CXX11 (RAPIDJSON_CPLUSPLUS >= 201103L)
+#endif
+
 #ifndef RAPIDJSON_HAS_CXX11_RVALUE_REFS
-#if defined(__clang__)
+#if RAPIDJSON_HAS_CXX11
+#define RAPIDJSON_HAS_CXX11_RVALUE_REFS 1
+#elif defined(__clang__)
 #if __has_feature(cxx_rvalue_references) && \
     (defined(_MSC_VER) || defined(_LIBCPP_VERSION) || defined(__GLIBCXX__) && __GLIBCXX__ >= 20080306)
 #define RAPIDJSON_HAS_CXX11_RVALUE_REFS 1
@@ -559,8 +596,14 @@ RAPIDJSON_NAMESPACE_END
 #endif
 #endif // RAPIDJSON_HAS_CXX11_RVALUE_REFS
 
+#if RAPIDJSON_HAS_CXX11_RVALUE_REFS
+#include <utility> // std::move
+#endif
+
 #ifndef RAPIDJSON_HAS_CXX11_NOEXCEPT
-#if defined(__clang__)
+#if RAPIDJSON_HAS_CXX11
+#define RAPIDJSON_HAS_CXX11_NOEXCEPT 1
+#elif defined(__clang__)
 #define RAPIDJSON_HAS_CXX11_NOEXCEPT __has_feature(cxx_noexcept)
 #elif (defined(RAPIDJSON_GNUC) && (RAPIDJSON_GNUC >= RAPIDJSON_VERSION_CODE(4,6,0)) && defined(__GXX_EXPERIMENTAL_CXX0X__)) || \
     (defined(_MSC_VER) && _MSC_VER >= 1900) || \
@@ -570,11 +613,13 @@ RAPIDJSON_NAMESPACE_END
 #define RAPIDJSON_HAS_CXX11_NOEXCEPT 0
 #endif
 #endif
+#ifndef RAPIDJSON_NOEXCEPT
 #if RAPIDJSON_HAS_CXX11_NOEXCEPT
 #define RAPIDJSON_NOEXCEPT noexcept
 #else
-#define RAPIDJSON_NOEXCEPT /* noexcept */
+#define RAPIDJSON_NOEXCEPT throw()
 #endif // RAPIDJSON_HAS_CXX11_NOEXCEPT
+#endif
 
 // no automatic detection, yet
 #ifndef RAPIDJSON_HAS_CXX11_TYPETRAITS
@@ -600,9 +645,17 @@ RAPIDJSON_NAMESPACE_END
 ///////////////////////////////////////////////////////////////////////////////
 // C++17 features
 
-#if defined(__has_cpp_attribute)
-# if __has_cpp_attribute(fallthrough)
-#  define RAPIDJSON_DELIBERATE_FALLTHROUGH [[fallthrough]]
+#ifndef RAPIDJSON_HAS_CXX17
+#define RAPIDJSON_HAS_CXX17 (RAPIDJSON_CPLUSPLUS >= 201703L)
+#endif
+
+#if RAPIDJSON_HAS_CXX17
+# define RAPIDJSON_DELIBERATE_FALLTHROUGH [[fallthrough]]
+#elif defined(__has_cpp_attribute)
+# if __has_cpp_attribute(clang::fallthrough)
+#  define RAPIDJSON_DELIBERATE_FALLTHROUGH [[clang::fallthrough]]
+# elif __has_cpp_attribute(fallthrough)
+#  define RAPIDJSON_DELIBERATE_FALLTHROUGH __attribute__((fallthrough))
 # else
 #  define RAPIDJSON_DELIBERATE_FALLTHROUGH
 # endif
@@ -628,12 +681,8 @@ RAPIDJSON_NAMESPACE_END
 
 #ifndef RAPIDJSON_NOEXCEPT_ASSERT
 #ifdef RAPIDJSON_ASSERT_THROWS
-#if RAPIDJSON_HAS_CXX11_NOEXCEPT
-#define RAPIDJSON_NOEXCEPT_ASSERT(x)
-#else
 #include <cassert>
 #define RAPIDJSON_NOEXCEPT_ASSERT(x) assert(x)
-#endif // RAPIDJSON_HAS_CXX11_NOEXCEPT
 #else
 #define RAPIDJSON_NOEXCEPT_ASSERT(x) RAPIDJSON_ASSERT(x)
 #endif // RAPIDJSON_ASSERT_THROWS