diff options
Diffstat (limited to 'contrib/llvm-project/libcxx/include/__algorithm/shift_right.h')
-rw-r--r-- | contrib/llvm-project/libcxx/include/__algorithm/shift_right.h | 123 |
1 files changed, 61 insertions, 62 deletions
diff --git a/contrib/llvm-project/libcxx/include/__algorithm/shift_right.h b/contrib/llvm-project/libcxx/include/__algorithm/shift_right.h index 70983e327bcb..73ef98bd39de 100644 --- a/contrib/llvm-project/libcxx/include/__algorithm/shift_right.h +++ b/contrib/llvm-project/libcxx/include/__algorithm/shift_right.h @@ -25,73 +25,72 @@ _LIBCPP_BEGIN_NAMESPACE_STD #if _LIBCPP_STD_VER >= 20 template <class _ForwardIterator> -inline _LIBCPP_HIDE_FROM_ABI constexpr -_ForwardIterator -shift_right(_ForwardIterator __first, _ForwardIterator __last, - typename iterator_traits<_ForwardIterator>::difference_type __n) -{ - if (__n == 0) { - return __first; - } +inline _LIBCPP_HIDE_FROM_ABI constexpr _ForwardIterator +shift_right(_ForwardIterator __first, + _ForwardIterator __last, + typename iterator_traits<_ForwardIterator>::difference_type __n) { + if (__n == 0) { + return __first; + } - if constexpr (__has_random_access_iterator_category<_ForwardIterator>::value) { - decltype(__n) __d = __last - __first; - if (__n >= __d) { - return __last; - } - _ForwardIterator __m = __first + (__d - __n); - return std::move_backward(__first, __m, __last); - } else if constexpr (__has_bidirectional_iterator_category<_ForwardIterator>::value) { - _ForwardIterator __m = __last; - for (; __n > 0; --__n) { - if (__m == __first) { - return __last; - } - --__m; - } - return std::move_backward(__first, __m, __last); - } else { - _ForwardIterator __ret = __first; - for (; __n > 0; --__n) { - if (__ret == __last) { - return __last; - } - ++__ret; - } + if constexpr (__has_random_access_iterator_category<_ForwardIterator>::value) { + decltype(__n) __d = __last - __first; + if (__n >= __d) { + return __last; + } + _ForwardIterator __m = __first + (__d - __n); + return std::move_backward(__first, __m, __last); + } else if constexpr (__has_bidirectional_iterator_category<_ForwardIterator>::value) { + _ForwardIterator __m = __last; + for (; __n > 0; --__n) { + if (__m == __first) { + return __last; + } + --__m; + } + return std::move_backward(__first, __m, __last); + } else { + _ForwardIterator __ret = __first; + for (; __n > 0; --__n) { + if (__ret == __last) { + return __last; + } + ++__ret; + } - // We have an __n-element scratch space from __first to __ret. - // Slide an __n-element window [__trail, __lead) from left to right. - // We're essentially doing swap_ranges(__first, __ret, __trail, __lead) - // over and over; but once __lead reaches __last we needn't bother - // to save the values of elements [__trail, __last). + // We have an __n-element scratch space from __first to __ret. + // Slide an __n-element window [__trail, __lead) from left to right. + // We're essentially doing swap_ranges(__first, __ret, __trail, __lead) + // over and over; but once __lead reaches __last we needn't bother + // to save the values of elements [__trail, __last). - auto __trail = __first; - auto __lead = __ret; - while (__trail != __ret) { - if (__lead == __last) { - std::move(__first, __trail, __ret); - return __ret; - } - ++__trail; - ++__lead; - } + auto __trail = __first; + auto __lead = __ret; + while (__trail != __ret) { + if (__lead == __last) { + std::move(__first, __trail, __ret); + return __ret; + } + ++__trail; + ++__lead; + } - _ForwardIterator __mid = __first; - while (true) { - if (__lead == __last) { - __trail = std::move(__mid, __ret, __trail); - std::move(__first, __mid, __trail); - return __ret; - } - swap(*__mid, *__trail); - ++__mid; - ++__trail; - ++__lead; - if (__mid == __ret) { - __mid = __first; - } - } + _ForwardIterator __mid = __first; + while (true) { + if (__lead == __last) { + __trail = std::move(__mid, __ret, __trail); + std::move(__first, __mid, __trail); + return __ret; + } + swap(*__mid, *__trail); + ++__mid; + ++__trail; + ++__lead; + if (__mid == __ret) { + __mid = __first; + } } + } } #endif // _LIBCPP_STD_VER >= 20 |