src/tint/utils/bytes/swap.h

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#ifndef SRC_TINT_UTILS_BYTES_SWAP_H_
#define SRC_TINT_UTILS_BYTES_SWAP_H_

#include <cstdint>
#include <cstring>
#include <type_traits>
#include <utility>

#include "src/tint/utils/macros/compiler.h"


namespace tint::bytes {

/// @returns the input value with all bytes reversed
/// @param value the input value, can be any type that passes std::is_integral
///              (this includes non-obvious types like wchar_t)
/// TODO(394825124): Once ranges from C++20 is available this code can be
///                  rewritten to avoid needing to disable warnings.
TINT_BEGIN_DISABLE_WARNING(UNSAFE_BUFFER_USAGE);
template <typename T>
[[nodiscard]] inline T Swap(T value) {
    static_assert(std::is_integral_v<T>);
    uint8_t bytes[sizeof(T)];
    memcpy(bytes, &value, sizeof(T));
    for (size_t i = 0; i < sizeof(T) / 2; i++) {
        std::swap(bytes[i], bytes[sizeof(T) - i - 1]);
    }
    T out;
    memcpy(&out, bytes, sizeof(T));
    return out;
}
TINT_END_DISABLE_WARNING(UNSAFE_BUFFER_USAGE);

}  // namespace tint::bytes


#endif  // SRC_TINT_UTILS_BYTES_SWAP_H_