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#pragma once
#include <cstring>
#include <type_traits>
#if __has_include(<bit>) && (__cplusplus >= 202002L || (defined(__cpp_lib_bit_cast) && __cpp_lib_bit_cast >= 201806L))
#include <bit>
#define C10_HAVE_STD_BIT_CAST 1
#else
#define C10_HAVE_STD_BIT_CAST 0
#endif // __has_include(<bit>) && (__cplusplus >= 202002L ||
// (defined(__cpp_lib_bit_cast) && __cpp_lib_bit_cast >= 201806L))
namespace c10 {
#if C10_HAVE_STD_BIT_CAST
using std::bit_cast;
#else
// Implementations of std::bit_cast() from C++ 20.
//
// This is a less sketchy version of reinterpret_cast.
//
// See https://en.cppreference.com/w/cpp/numeric/bit_cast for more
// information as well as the source of our implementations.
template <class To, class From>
std::enable_if_t<
sizeof(To) == sizeof(From) && std::is_trivially_copyable_v<From> &&
std::is_trivially_copyable_v<To>,
To>
// constexpr support needs compiler magic
bit_cast(const From& src) noexcept {
static_assert(
std::is_trivially_constructible_v<To>,
"This implementation additionally requires "
"destination type to be trivially constructible");
To dst;
std::memcpy(&dst, &src, sizeof(To));
return dst;
}
#endif // C10_HAVE_STD_BIT_CAST
#undef C10_HAVE_STD_BIT_CAST
} // namespace c10
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