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add C++14 constexpr set/heap/permutation algorithms

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bolero-MURAKAMI 2014-04-06 18:37:06 +09:00
parent ecccb58042
commit 098dd1721e
13 changed files with 649 additions and 11 deletions
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64
sprout/algorithm/cxx14/prev_permutation.hpp Normal file
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/*=============================================================================
Copyright (c) 2011-2014 Bolero MURAKAMI
https://github.com/bolero-MURAKAMI/Sprout
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)
=============================================================================*/
#ifndef SPROUT_ALGORITHM_CXX14_PREV_PERMUTATION_HPP
#define SPROUT_ALGORITHM_CXX14_PREV_PERMUTATION_HPP
#include <iterator>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/algorithm/cxx14/reverse.hpp>
#include <sprout/utility/swap.hpp>
#include HDR_FUNCTIONAL_SSCRISK_CEL_OR_SPROUT
namespace sprout {
namespace detail {
template<typename Compare, typename BidirectionalIterator>
inline SPROUT_CXX14_CONSTEXPR bool
prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp) {
BidirectionalIterator i = last;
if (first == last || first == --i) {
return false;
}
while (true) {
BidirectionalIterator ip1 = i;
if (comp(*ip1, *--i)) {
BidirectionalIterator j = last;
while (!comp(*--j, *i))
;
sprout::swap(*i, *j);
sprout::reverse(ip1, last);
return true;
}
if (i == first) {
sprout::reverse(first, last);
return false;
}
}
}
} // namespace detail
//
// 25.4.9 Permutation generators
//
template<typename BidirectionalIterator, typename Compare>
inline SPROUT_CXX14_CONSTEXPR bool
prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp) {
typedef typename std::add_lvalue_reference<Compare>::type compare_ref;
return sprout::detail::prev_permutation<compare_ref>(first, last, comp);
}
template<typename BidirectionalIterator>
inline SPROUT_CXX14_CONSTEXPR bool
prev_permutation(BidirectionalIterator first, BidirectionalIterator last) {
return sprout::prev_permutation(
first, last,
NS_SSCRISK_CEL_OR_SPROUT::less<typename std::iterator_traits<BidirectionalIterator>::value_type>()
);
}
} // namespace sprout
#endif // #ifndef SPROUT_ALGORITHM_CXX14_PREV_PERMUTATION_HPP