48 lines
1.1 KiB
C++
48 lines
1.1 KiB
C++
#pragma once
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#include <bit>
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#include <base/types.hpp>
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namespace base {
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// required until C++23 support :(
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namespace detail {
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template <class T, class U>
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constexpr T PunCast(U v) {
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return *std::bit_cast<const T*>(&v);
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}
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template <class T>
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constexpr T ByteSwap(T v) {
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if constexpr(sizeof(T) == 2)
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return static_cast<T>(__builtin_bswap16(PunCast<u16>(v)));
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else if constexpr(sizeof(T) == 4)
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return static_cast<T>(__builtin_bswap32(PunCast<u32>(v)));
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else if constexpr(sizeof(T) == 8)
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return static_cast<T>(__builtin_bswap64(PunCast<u64>(v)));
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return v;
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}
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} // namespace detail
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/// A network-order field, swapped automatically
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template <class T>
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struct [[gnu::packed]] NetworkOrder {
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constexpr NetworkOrder() = default;
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constexpr NetworkOrder(T v) : field(SwapIfRequired(v)) {}
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operator T() const { return SwapIfRequired(field); }
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private:
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constexpr static T SwapIfRequired(T value) {
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if constexpr(std::endian::native == std::endian::little)
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return detail::ByteSwap(value);
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return value;
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}
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T field;
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};
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} // namespace base
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