diff options
Diffstat (limited to 'libcxx/include/__algorithm/copy_backward.h')
| -rw-r--r-- | libcxx/include/__algorithm/copy_backward.h | 66 |
1 files changed, 20 insertions, 46 deletions
diff --git a/libcxx/include/__algorithm/copy_backward.h b/libcxx/include/__algorithm/copy_backward.h index ac733290abe4..dd43a91ffa87 100644 --- a/libcxx/include/__algorithm/copy_backward.h +++ b/libcxx/include/__algorithm/copy_backward.h @@ -9,69 +9,43 @@ #ifndef _LIBCPP___ALGORITHM_COPY_BACKWARD_H #define _LIBCPP___ALGORITHM_COPY_BACKWARD_H +#include <__algorithm/copy.h> #include <__algorithm/unwrap_iter.h> #include <__config> #include <__iterator/iterator_traits.h> +#include <__iterator/reverse_iterator.h> #include <cstring> #include <type_traits> #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) -#pragma GCC system_header +# pragma GCC system_header #endif _LIBCPP_BEGIN_NAMESPACE_STD -template <class _BidirectionalIterator, class _OutputIterator> -inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 -_OutputIterator -__copy_backward_constexpr(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result) -{ - while (__first != __last) - *--__result = *--__last; - return __result; +template <class _Iter1, class _Sent1, class _Iter2> +inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 +pair<_Iter1, _Iter2> __copy_backward_impl(_Iter1 __first, _Sent1 __last, _Iter2 __result) { + auto __ret = std::__copy(reverse_iterator<_Iter1>(__last), + reverse_iterator<_Sent1>(__first), + reverse_iterator<_Iter2>(__result)); + return pair<_Iter1, _Iter2>(__ret.first.base(), __ret.second.base()); } -template <class _BidirectionalIterator, class _OutputIterator> -inline _LIBCPP_INLINE_VISIBILITY -_OutputIterator -__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result) -{ - return _VSTD::__copy_backward_constexpr(__first, __last, __result); -} - -template <class _Tp, class _Up> -inline _LIBCPP_INLINE_VISIBILITY -typename enable_if -< - is_same<typename remove_const<_Tp>::type, _Up>::value && - is_trivially_copy_assignable<_Up>::value, - _Up* ->::type -__copy_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 _Iter1, class _Sent1, class _Iter2> +inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 +pair<_Iter1, _Iter2> __copy_backward(_Iter1 __first, _Sent1 __last, _Iter2 __result) { + auto __ret = std::__copy_backward_impl(std::__unwrap_iter(__first), + std::__unwrap_iter(__last), + std::__unwrap_iter(__result)); + return pair<_Iter1, _Iter2>(std::__rewrap_iter(__first, __ret.first), std::__rewrap_iter(__result, __ret.second)); } template <class _BidirectionalIterator1, class _BidirectionalIterator2> -inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 +inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator2 -copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last, - _BidirectionalIterator2 __result) -{ - if (__libcpp_is_constant_evaluated()) { - return _VSTD::__copy_backward_constexpr(__first, __last, __result); - } else { - return _VSTD::__rewrap_iter(__result, - _VSTD::__copy_backward(_VSTD::__unwrap_iter(__first), - _VSTD::__unwrap_iter(__last), - _VSTD::__unwrap_iter(__result))); - } +copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last, _BidirectionalIterator2 __result) { + return std::__copy_backward(__first, __last, __result).second; } _LIBCPP_END_NAMESPACE_STD |