CopyableHeapBlock: Add initial implementation

modules/juce_core/juce_core.h

@@ -258,6 +258,7 @@ JUCE_END_IGNORE_WARNINGS_MSVC
 #include "memory/juce_ContainerDeletePolicy.h"
 #include "memory/juce_HeapBlock.h"
 #include "memory/juce_MemoryBlock.h"
+#include "memory/juce_CopyableHeapBlock.h"
 #include "memory/juce_ReferenceCountedObject.h"
 #include "memory/juce_ScopedPointer.h"
 #include "memory/juce_OptionalScopedPointer.h"

modules/juce_core/memory/juce_CopyableHeapBlock.h

@@ -0,0 +1,180 @@
+/*
+  ==============================================================================
+
+   This file is part of the JUCE framework.
+   Copyright (c) Raw Material Software Limited
+
+   JUCE is an open source framework subject to commercial or open source
+   licensing.
+
+   By downloading, installing, or using the JUCE framework, or combining the
+   JUCE framework with any other source code, object code, content or any other
+   copyrightable work, you agree to the terms of the JUCE End User Licence
+   Agreement, and all incorporated terms including the JUCE Privacy Policy and
+   the JUCE Website Terms of Service, as applicable, which will bind you. If you
+   do not agree to the terms of these agreements, we will not license the JUCE
+   framework to you, and you must discontinue the installation or download
+   process and cease use of the JUCE framework.
+
+   JUCE End User Licence Agreement: https://juce.com/legal/juce-8-licence/
+   JUCE Privacy Policy: https://juce.com/juce-privacy-policy
+   JUCE Website Terms of Service: https://juce.com/juce-website-terms-of-service/
+
+   Or:
+
+   You may also use this code under the terms of the AGPLv3:
+   https://www.gnu.org/licenses/agpl-3.0.en.html
+
+   THE JUCE FRAMEWORK IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL
+   WARRANTIES, WHETHER EXPRESSED OR IMPLIED, INCLUDING WARRANTY OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED.
+
+  ==============================================================================
+*/
+
+namespace juce
+{
+
+/** Wraps a HeapBlock, but additionally provides a copy constructor and remembers its size.
+
+    This class is not intended for use as a general-purpose container - in most cases, a std::vector
+    or juce::Array is a better choice. However, CopyableHeapBlock may be handy for optimisation in
+    situations where the container elements don't need to be value-initialised and the container
+    doesn't need to be resized.
+
+    @see Array, OwnedArray, MemoryBlock, HeapBlock
+
+    @tags{Core}
+*/
+template <typename ElementType, bool throwOnFailure = false>
+class CopyableHeapBlock
+{
+public:
+    static_assert (std::is_trivially_copyable_v<ElementType>);
+
+    /** Creates an empty block. */
+    CopyableHeapBlock() = default;
+
+    /** Creates a block large enough to hold the specified number of elements.
+
+        The contents of the block are unspecified, and *must* be written before they are first read.
+    */
+    explicit CopyableHeapBlock (size_t numElementsIn)
+        : block (numElementsIn),
+          numElements (numElementsIn)
+    {
+    }
+
+    /** Moves the contents of another block into this one. */
+    CopyableHeapBlock (CopyableHeapBlock&& other) noexcept
+        : block (std::exchange (other.block, {})),
+          numElements (std::exchange (other.numElements, {}))
+    {
+    }
+
+    /** Copies the contents of another block into this one. */
+    CopyableHeapBlock (const CopyableHeapBlock& other)
+        : block (other.numElements),
+          numElements (other.numElements)
+    {
+        std::copy (other.block.getData(), other.block.getData() + other.numElements, block.getData());
+    }
+
+    /** Moves the contents of another block into this one. */
+    CopyableHeapBlock& operator= (CopyableHeapBlock&& other) noexcept
+    {
+        CopyableHeapBlock { std::move (other) }.swap (*this);
+        return *this;
+    }
+
+    /** Copies the contents of another block into this one. */
+    CopyableHeapBlock& operator= (const CopyableHeapBlock& other) noexcept
+    {
+        CopyableHeapBlock { other }.swap (*this);
+        return *this;
+    }
+
+    /** Returns a pointer to the first element in the block. */
+    ElementType* data()
+    {
+        return block.getData();
+    }
+
+    /** Returns a pointer to the first element in the block. */
+    const ElementType* data() const
+    {
+        return block.getData();
+    }
+
+    /** Returns the number of elements in the block. */
+    size_t size() const
+    {
+        return numElements;
+    }
+
+    /** Returns true if the size of the block is zero. */
+    bool isEmpty() const
+    {
+        return size() == 0;
+    }
+
+    /** Returns a pointer to the first element in the block. */
+    ElementType* begin()
+    {
+        return data();
+    }
+
+    /** Returns a pointer to the first element in the block. */
+    const ElementType* begin() const
+    {
+        return data();
+    }
+
+    /** Returns a pointer to the first element in the block. */
+    const ElementType* cbegin() const
+    {
+        return data();
+    }
+
+    /** Returns a pointer immediately after the last element in the block. */
+    ElementType* end()
+    {
+        return data() + size();
+    }
+
+    /** Returns a pointer immediately after the last element in the block. */
+    const ElementType* end() const
+    {
+        return data() + size();
+    }
+
+    /** Returns a pointer immediately after the last element in the block. */
+    const ElementType* cend() const
+    {
+        return data() + size();
+    }
+
+    /** Returns a reference to the element at the provided index. */
+    ElementType& operator[] (size_t index)
+    {
+        return data()[index];
+    }
+
+    /** Returns a reference to the element at the provided index. */
+    const ElementType& operator[] (size_t index) const
+    {
+        return data()[index];
+    }
+
+private:
+    void swap (CopyableHeapBlock& other) noexcept
+    {
+        std::swap (other.block, block);
+        std::swap (other.numElements, numElements);
+    }
+
+    HeapBlock<ElementType, throwOnFailure> block;
+    size_t numElements{};
+};
+
+} // namespace juce