37 lines
1.5 KiB
C++
37 lines
1.5 KiB
C++
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// This file is part of the mcl project.
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// Copyright (c) 2022 merryhime
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// SPDX-License-Identifier: MIT
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#pragma once
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#include <cstring>
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#include <type_traits>
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namespace mcl {
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/// Reinterpret objects of one type as another by bit-casting between object representations.
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template<class Dest, class Source>
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inline Dest bit_cast(const Source& source) noexcept {
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static_assert(sizeof(Dest) == sizeof(Source), "size of destination and source objects must be equal");
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static_assert(std::is_trivially_copyable_v<Dest>, "destination type must be trivially copyable.");
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static_assert(std::is_trivially_copyable_v<Source>, "source type must be trivially copyable");
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std::aligned_storage_t<sizeof(Dest), alignof(Dest)> dest;
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std::memcpy(&dest, &source, sizeof(dest));
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return reinterpret_cast<Dest&>(dest);
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}
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/// Reinterpret objects of any arbitrary type as another type by bit-casting between object representations.
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/// Note that here we do not verify if source pointed to by source_ptr has enough bytes to read from.
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template<class Dest, class SourcePtr>
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inline Dest bit_cast_pointee(const SourcePtr source_ptr) noexcept {
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static_assert(sizeof(SourcePtr) == sizeof(void*), "source pointer must have size of a pointer");
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static_assert(std::is_trivially_copyable_v<Dest>, "destination type must be trivially copyable.");
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std::aligned_storage_t<sizeof(Dest), alignof(Dest)> dest;
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std::memcpy(&dest, bit_cast<void*>(source_ptr), sizeof(dest));
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return reinterpret_cast<Dest&>(dest);
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}
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} // namespace mcl
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