/
fnv1a.hpp
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/
fnv1a.hpp
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// Copyright (c) 2010-2023 niXman (github dot nixman at pm dot me). All
// rights reserved.
//
// This file is part of YAS(https://github.com/niXman/yas) project.
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
//
//
// Boost Software License - Version 1.0 - August 17th, 2003
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
#ifndef __yas__detail__type_traits__fnv1a_hpp
#define __yas__detail__type_traits__fnv1a_hpp
#include <yas/detail/tools/cast.hpp>
#include <cstdint>
namespace yas {
namespace detail {
/***************************************************************************/
constexpr std::uint32_t fnv1a(std::nullptr_t) { return 0; }
#if __cplusplus >= 201402L && !defined(_MSC_VER)
template<typename CharT>
constexpr std::uint32_t fnv1a(const CharT *s) {
std::uint32_t seed = 0x811c9dc5;
for ( ; *s; ++s ) {
seed = __YAS_SCAST(
std::uint32_t
,((seed ^ __YAS_SCAST(std::uint32_t, *s)) * __YAS_SCAST(std::uint64_t, 0x01000193))
);
}
return seed;
}
#else // __cplusplus < 201402L
template<typename CharT>
constexpr std::uint32_t fnv1a(const CharT *s, std::uint32_t h = 0x811c9dc5) {
return (*s == 0)
? h
: fnv1a(
s+1
,__YAS_SCAST(std::uint32_t, ((h ^ __YAS_SCAST(std::uint32_t, *s)) * __YAS_SCAST(std::uint64_t, 0x01000193)))
)
;
}
#endif // __cplusplus >= 201402L
/***************************************************************************/
} // ns detail
} // ns yas
#endif // __yas__detail__type_traits__fnv1a_hpp