mirror of
https://github.com/bolero-MURAKAMI/Sprout.git
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58 lines
1.5 KiB
C++
58 lines
1.5 KiB
C++
/*=============================================================================
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Copyright (c) 2011-2018 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_ROTATE_HPP
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#define SPROUT_ALGORITHM_CXX14_ROTATE_HPP
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#include <iterator>
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#include <sprout/config.hpp>
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#include <sprout/algorithm/cxx14/iter_swap.hpp>
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namespace sprout {
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//
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// 25.3.11 Rotate
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//
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template<typename ForwardIterator>
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inline SPROUT_CXX14_CONSTEXPR ForwardIterator
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rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last) {
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if (first == middle) {
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return last;
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} else if (middle == last) {
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return first;
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}
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ForwardIterator first2 = middle;
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while (true) {
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sprout::iter_swap(first, first2);
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++first;
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if (++first2 == last) {
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break;
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}
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if (first == middle) {
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middle = first2;
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}
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}
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ForwardIterator result = first;
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if (first != middle) {
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first2 = middle;
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while (true) {
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sprout::iter_swap(first, first2);
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++first;
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if (++first2 == last) {
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if (first == middle) {
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break;
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}
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first2 = middle;
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} else if (first == middle) {
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middle = first2;
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}
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}
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}
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return result;
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_ALGORITHM_CXX14_ROTATE_HPP
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