mirror of
https://github.com/bolero-MURAKAMI/Sprout
synced 2024-11-12 21:09:01 +00:00
40 lines
1.6 KiB
C++
40 lines
1.6 KiB
C++
/*=============================================================================
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Copyright (c) 2011-2016 Bolero MURAKAMI
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https://github.com/bolero-MURAKAMI/Sprout
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Distributed under the Boost Software License, Version 1.0. (See accompanying
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file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================*/
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#ifndef SPROUT_ALGORITHM_CXX14_SHUFFLE_HPP
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#define SPROUT_ALGORITHM_CXX14_SHUFFLE_HPP
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#include <iterator>
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#include <sprout/config.hpp>
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#include <sprout/workaround/std/cstddef.hpp>
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#include <sprout/algorithm/cxx14/iter_swap.hpp>
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#include <sprout/workaround/detail/uniform_int_distribution.hpp>
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namespace sprout {
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//
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// 25.3.12 Random shuffle
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//
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template<typename RandomAccessIterator, typename UniformRandomNumberGenerator>
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inline SPROUT_CXX14_CONSTEXPR void
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shuffle(RandomAccessIterator first, RandomAccessIterator last, UniformRandomNumberGenerator&& g) {
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typedef typename std::iterator_traits<RandomAccessIterator>::difference_type difference_type;
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typedef SPROUT_WORKAROUND_DETAIL_UNIFORM_INT_DISTRIBUTION<std::ptrdiff_t> distribution_type;
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typedef typename distribution_type::param_type param_type;
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difference_type d = last - first;
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if (d > 1) {
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distribution_type dist;
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for (--last, --d; first < last; ++first, --d) {
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difference_type i = dist(g, param_type(0, d));
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if (i != difference_type(0)) {
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sprout::iter_swap(first, first + i);
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}
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}
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}
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_ALGORITHM_CXX14_SHUFFLE_HPP
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