Sprout/sprout/algorithm/rotate.hpp
bolero-MURAKAMI c58c9cc0fc fix: math functions (support for inferior C++14 standard)
add C++14 constexpr modifying algorithms
2013-10-25 12:29:16 +09:00

61 lines
1.6 KiB
C++

/*=============================================================================
Copyright (c) 2011-2013 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_ROTATE_HPP
#define SPROUT_ALGORITHM_ROTATE_HPP
#include <iterator>
#include <sprout/config.hpp>
#include <sprout/algorithm/iter_swap.hpp>
namespace sprout {
//
// 25.3.11 Rotate
//
template<typename ForwardIterator>
inline SPROUT_CXX14_CONSTEXPR ForwardIterator
rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last) {
if (first == middle) {
return last;
} else if (middle == last) {
return first;
}
ForwardIterator first2 = middle;
while (true) {
sprout::iter_swap(first, first2);
++first;
if (++first2 == last) {
break;
}
if (first == middle) {
middle = first2;
}
}
ForwardIterator result = first;
if (first != middle) {
first2 = middle;
while (true) {
sprout::iter_swap(first, first2);
++first;
if (++first2 == last) {
if (first == middle) {
break;
}
first2 = middle;
} else if (first == middle) {
middle = first2;
}
}
}
return result;
}
} // namespace sprout
#include <sprout/algorithm/fixed/rotate.hpp>
#include <sprout/algorithm/fit/rotate.hpp>
#endif // #ifndef SPROUT_ALGORITHM_ROTATE_HPP