forked from boostorg/unordered
53 lines
1.2 KiB
C++
53 lines
1.2 KiB
C++
/* Hash function characterization.
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*
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* Copyright 2022 Joaquin M Lopez Munoz.
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* Distributed under the Boost Software License, Version 1.0.
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* (See accompanying file LICENSE_1_0.txt or copy at
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* http://www.boost.org/LICENSE_1_0.txt)
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*
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* See https://www.boost.org/libs/unordered for library home page.
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*/
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#ifndef BOOST_UNORDERED_HASH_TRAITS_HPP
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#define BOOST_UNORDERED_HASH_TRAITS_HPP
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#include <boost/type_traits/make_void.hpp>
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#include <type_traits>
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namespace boost{
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namespace unordered{
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namespace detail{
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template<typename Hash,typename=void>
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struct hash_is_avalanching
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{
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using type=std::false_type;
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};
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template<typename Hash>
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struct hash_is_avalanching<Hash,void_t<typename Hash::is_avalanching>>
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{
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using type=std::true_type;
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};
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} /* namespace detail */
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/* Partially specializable by users for concrete hash functions when
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* actual characterization differs from default.
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*/
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template<typename Hash>
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struct hash_traits
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{
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/* std::true_type if the type Hash::is_avalanching is present,
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* std::false_type otherwise.
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*/
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using is_avalanching=typename detail::hash_is_avalanching<Hash>::type;
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};
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} /* namespace unordered */
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} /* namespace boost */
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#endif
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