85 lines
1.5 KiB
C++
85 lines
1.5 KiB
C++
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#pragma once
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#include <cstddef>
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#include <cstdint>
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#include <string_view>
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#include <type_traits>
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namespace rage
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{
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using joaat_t = std::uint32_t;
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inline constexpr char joaat_to_lower(char c)
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{
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return (c >= 'A' && c <= 'Z') ? c + ('a' - 'A') : c;
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}
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template <std::size_t CharCount>
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struct constexpr_joaat
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{
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char data[CharCount];
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template <std::size_t... Indices>
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constexpr constexpr_joaat(const char *str, std::index_sequence<Indices...>) :
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data{ (str[Indices])... }
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{
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}
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constexpr joaat_t operator()()
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{
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joaat_t hash = 0;
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for (std::size_t i = 0; i < CharCount; ++i)
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{
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hash += joaat_to_lower(data[i]);
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hash += (hash << 10);
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hash ^= (hash >> 6);
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}
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hash += (hash << 3);
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hash ^= (hash >> 11);
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hash += (hash << 15);
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return hash;
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}
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};
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inline joaat_t joaat(std::string_view str)
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{
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joaat_t hash = 0;
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for (char c : str)
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{
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hash += joaat_to_lower(c);
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hash += (hash << 10);
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hash ^= (hash >> 6);
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}
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hash += (hash << 3);
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hash ^= (hash >> 11);
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hash += (hash << 15);
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return hash;
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}
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inline joaat_t joaat(const char *str)
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{
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joaat_t hash = 0;
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while (*str)
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{
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hash += joaat_to_lower(*(str++));
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hash += (hash << 10);
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hash ^= (hash >> 6);
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}
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hash += (hash << 3);
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hash ^= (hash >> 11);
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hash += (hash << 15);
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return hash;
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}
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}
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#define RAGE_JOAAT_IMPL(str) (::rage::constexpr_joaat<sizeof(str) - 1>((str), std::make_index_sequence<sizeof(str) - 1>())())
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#define RAGE_JOAAT(str) (std::integral_constant<rage::joaat_t, RAGE_JOAAT_IMPL(str)>::value)
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