| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #ifndef _LIBCPP___ALGORITHM_MOVE_BACKWARD_H |
| #define _LIBCPP___ALGORITHM_MOVE_BACKWARD_H |
| |
| #include <__config> |
| #include <__algorithm/unwrap_iter.h> |
| #include <cstring> |
| #include <utility> |
| #include <type_traits> |
| |
| #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) |
| #pragma GCC system_header |
| #endif |
| |
| _LIBCPP_BEGIN_NAMESPACE_STD |
| |
| template <class _InputIterator, class _OutputIterator> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| _OutputIterator |
| __move_backward_constexpr(_InputIterator __first, _InputIterator __last, _OutputIterator __result) |
| { |
| while (__first != __last) |
| *--__result = _VSTD::move(*--__last); |
| return __result; |
| } |
| |
| template <class _InputIterator, class _OutputIterator> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| _OutputIterator |
| __move_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result) |
| { |
| return _VSTD::__move_backward_constexpr(__first, __last, __result); |
| } |
| |
| template <class _Tp, class _Up> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 |
| typename enable_if |
| < |
| is_same<typename remove_const<_Tp>::type, _Up>::value && |
| is_trivially_move_assignable<_Up>::value, |
| _Up* |
| >::type |
| __move_backward(_Tp* __first, _Tp* __last, _Up* __result) |
| { |
| const size_t __n = static_cast<size_t>(__last - __first); |
| if (__n > 0) |
| { |
| __result -= __n; |
| _VSTD::memmove(__result, __first, __n * sizeof(_Up)); |
| } |
| return __result; |
| } |
| |
| template <class _BidirectionalIterator1, class _BidirectionalIterator2> |
| inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 |
| _BidirectionalIterator2 |
| move_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last, |
| _BidirectionalIterator2 __result) |
| { |
| if (__libcpp_is_constant_evaluated()) { |
| return _VSTD::__move_backward_constexpr(__first, __last, __result); |
| } else { |
| return _VSTD::__rewrap_iter(__result, |
| _VSTD::__move_backward(_VSTD::__unwrap_iter(__first), |
| _VSTD::__unwrap_iter(__last), |
| _VSTD::__unwrap_iter(__result))); |
| } |
| } |
| |
| _LIBCPP_END_NAMESPACE_STD |
| |
| #endif // _LIBCPP___ALGORITHM_MOVE_BACKWARD_H |