21 lines
709 B
C++
21 lines
709 B
C++
#pragma once
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#include <stdint.h>
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// FNV1a c++11 constexpr compile time hash functions, 32 and 64 bit
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// str should be a null terminated string literal, value should be left out
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// e.g hash_32_fnv1a_const("example")
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// code license: public domain or equivalent
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// post: https://notes.underscorediscovery.com/constexpr-fnv1a/
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constexpr uint32_t val_32_const = 0x811c9dc5;
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constexpr uint32_t prime_32_const = 0x1000193;
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inline constexpr uint32_t hash_32_fnv1a_const(const char* const str, const uint32_t value = val_32_const) noexcept
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{
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return (str[0] == '\0') ? value : hash_32_fnv1a_const(&str[1], (value ^ uint32_t(str[0])) * prime_32_const);
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}
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// life do be like that
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#define HASH hash_32_fnv1a_const
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