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/*
* Copyright (C) 2025 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include <span>
#include <wtf/Noncopyable.h>
#include <wtf/StdLibExtras.h>
namespace WTF {
// Mixin for implementing RAII holders for memory that has custom alloc and free functionality.
template<typename T> class AllocSpanMixin {
WTF_MAKE_NONCOPYABLE(AllocSpanMixin);
public:
AllocSpanMixin(AllocSpanMixin&& other)
: m_span(other.leakSpan())
{
}
void swap(AllocSpanMixin& other)
{
std::swap(m_span, other.m_span);
}
size_t sizeInBytes() const { return m_span.size_bytes(); }
std::span<const T> span() const LIFETIME_BOUND { return m_span; }
std::span<T> mutableSpan() LIFETIME_BOUND { return m_span; }
std::span<T> leakSpan() WARN_UNUSED_RETURN { return std::exchange(m_span, std::span<T> { }); }
T& operator[](size_t i) LIFETIME_BOUND { return m_span[i]; }
const T& operator[](size_t i) const LIFETIME_BOUND { return m_span[i]; }
explicit operator bool() const
{
return !!m_span.data();
}
bool operator!() const
{
return !m_span.data();
}
protected:
AllocSpanMixin() = default;
explicit AllocSpanMixin(std::span<T> span)
: m_span(span)
{
}
explicit AllocSpanMixin(void* ptr, size_t sizeInBytes)
: m_span(unsafeMakeSpan(static_cast<T*>(ptr), sizeInBytes / sizeof(T)))
{
RELEASE_ASSERT(!(sizeInBytes % sizeof(T)));
}
private:
std::span<T> m_span;
};
}
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