Add rvalue copy and assignment to MemoryPoolAllocator and StdAllocator.

Author: ylavic

include/rapidjson/allocators.h

@@ -222,18 +222,42 @@ class MemoryPoolAllocator {
     {
         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() RAPIDJSON_NOEXCEPT {
+        if (!shared_) {
+            // do nothing if moved
+            return;
+        }
         if (shared_->refcount > 1) {
             --shared_->refcount;
             return;
@@ -449,6 +473,17 @@ class StdAllocator :
         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(),
@@ -549,6 +584,10 @@ class StdAllocator :
         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
     {
@@ -561,6 +600,7 @@ class StdAllocator :
     }
 
     //! rapidjson Allocator concept
+    static const bool kNeedFree = BaseAllocator::kNeedFree;
     void* Malloc(size_t size)
     {
         return baseAllocator_.Malloc(size);