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little hash combiner cleanup

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BlackMATov
2024-02-05 00:58:40 +07:00
parent 02089116b9
commit e2f287420a
1 changed files with 11 additions and 3 deletions
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14
headers/meta.hpp/meta_base/hash_combiner.hpp
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@@ -12,14 +12,22 @@ namespace meta_hpp::detail
{
struct hash_combiner {
template < typename T >
[[nodiscard]] std::size_t operator()(const T& x) noexcept {
[[nodiscard]] std::size_t operator()(const T& x) const noexcept {
return std::hash<T>{}(x);
}
template < typename T >
[[nodiscard]] std::size_t operator()(std::size_t seed, const T& x) noexcept {
requires(sizeof(std::size_t) == sizeof(std::uint32_t))
[[nodiscard]] std::size_t operator()(std::size_t seed, const T& x) const noexcept {
// NOLINTNEXTLINE(*-magic-numbers)
return (seed ^= std::hash<T>{}(x) + 0x9e3779b9 + (seed << 6) + (seed >> 2));
return (seed ^= std::hash<T>{}(x) + 0x9e3779b9U + (seed << 6) + (seed >> 2));
}
template < typename T >
requires(sizeof(std::size_t) == sizeof(std::uint64_t))
[[nodiscard]] std::size_t operator()(std::size_t seed, const T& x) const noexcept {
// NOLINTNEXTLINE(*-magic-numbers)
return (seed ^= std::hash<T>{}(x) + 0x9e3779b97f4a7c15LLU + (seed << 12) + (seed >> 4));
}
};
}