1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___ALGORITHM_COPY_H 10 #define _LIBCPP___ALGORITHM_COPY_H 11 12 #include <__algorithm/unwrap_iter.h> 13 #include <__config> 14 #include <__iterator/iterator_traits.h> 15 #include <__iterator/reverse_iterator.h> 16 #include <__utility/move.h> 17 #include <__utility/pair.h> 18 #include <cstring> 19 #include <type_traits> 20 21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 22 # pragma GCC system_header 23 #endif 24 25 _LIBCPP_BEGIN_NAMESPACE_STD 26 27 // copy 28 29 template <class _InIter, class _Sent, class _OutIter> 30 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 31 pair<_InIter, _OutIter> __copy_impl(_InIter __first, _Sent __last, _OutIter __result) { 32 while (__first != __last) { 33 *__result = *__first; 34 ++__first; 35 ++__result; 36 } 37 return pair<_InIter, _OutIter>(std::move(__first), std::move(__result)); 38 } 39 40 template <class _InValueT, 41 class _OutValueT, 42 class = __enable_if_t<is_same<typename remove_const<_InValueT>::type, _OutValueT>::value 43 && is_trivially_copy_assignable<_OutValueT>::value> > 44 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 45 pair<_InValueT*, _OutValueT*> __copy_impl(_InValueT* __first, _InValueT* __last, _OutValueT* __result) { 46 if (__libcpp_is_constant_evaluated() 47 // TODO: Remove this once GCC supports __builtin_memmove during constant evaluation 48 #ifndef _LIBCPP_COMPILER_GCC 49 && !is_trivially_copyable<_InValueT>::value 50 #endif 51 ) 52 return std::__copy_impl<_InValueT*, _InValueT*, _OutValueT*>(__first, __last, __result); 53 const size_t __n = static_cast<size_t>(__last - __first); 54 if (__n > 0) 55 ::__builtin_memmove(__result, __first, __n * sizeof(_OutValueT)); 56 return std::make_pair(__first + __n, __result + __n); 57 } 58 59 template <class _Iter> 60 using __is_trivially_copy_assignable_unwrapped = 61 _And<__is_cpp17_contiguous_iterator<_Iter>, is_trivially_copy_assignable<__iter_value_type<_Iter> > >; 62 63 template <class _InIter, 64 class _OutIter, 65 class = __enable_if_t<is_same<typename remove_const<typename iterator_traits<_InIter>::value_type>::type, 66 typename iterator_traits<_OutIter>::value_type>::value 67 && __is_trivially_copy_assignable_unwrapped<_InIter>::value 68 && __is_trivially_copy_assignable_unwrapped<_OutIter>::value> > 69 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 70 pair<reverse_iterator<_InIter>, reverse_iterator<_OutIter> > 71 __copy_impl(reverse_iterator<_InIter> __first, 72 reverse_iterator<_InIter> __last, 73 reverse_iterator<_OutIter> __result) { 74 auto __first_base = std::__unwrap_iter(__first.base()); 75 auto __last_base = std::__unwrap_iter(__last.base()); 76 auto __result_base = std::__unwrap_iter(__result.base()); 77 auto __result_first = __result_base - (__first_base - __last_base); 78 std::__copy_impl(__last_base, __first_base, __result_first); 79 return std::make_pair(__last, reverse_iterator<_OutIter>(std::__rewrap_iter(__result.base(), __result_first))); 80 } 81 82 template <class _InIter, class _Sent, class _OutIter> 83 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 84 pair<reverse_iterator<reverse_iterator<_InIter> >, reverse_iterator<reverse_iterator<_OutIter> > > 85 __copy_impl(reverse_iterator<reverse_iterator<_InIter> > __first, 86 reverse_iterator<reverse_iterator<_Sent> > __last, 87 reverse_iterator<reverse_iterator<_OutIter> > __result); 88 89 template <class _InIter, class _Sent, class _OutIter, 90 __enable_if_t<!(is_copy_constructible<_InIter>::value 91 && is_copy_constructible<_Sent>::value 92 && is_copy_constructible<_OutIter>::value), int> = 0 > 93 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 94 pair<_InIter, _OutIter> __copy(_InIter __first, _Sent __last, _OutIter __result) { 95 return std::__copy_impl(std::move(__first), std::move(__last), std::move(__result)); 96 } 97 98 template <class _InIter, class _Sent, class _OutIter, 99 __enable_if_t<is_copy_constructible<_InIter>::value 100 && is_copy_constructible<_Sent>::value 101 && is_copy_constructible<_OutIter>::value, int> = 0> 102 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 103 pair<_InIter, _OutIter> 104 __copy(_InIter __first, _Sent __last, _OutIter __result) { 105 auto __ret = std::__copy_impl(std::__unwrap_iter(__first), std::__unwrap_iter(__last), std::__unwrap_iter(__result)); 106 return std::make_pair(std::__rewrap_iter(__first, __ret.first), std::__rewrap_iter(__result, __ret.second)); 107 } 108 109 // __unwrap_iter can't unwrap random_access_iterators, so we need to unwrap two reverse_iterators manually 110 template <class _InIter, class _Sent, class _OutIter> 111 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11 112 pair<reverse_iterator<reverse_iterator<_InIter> >, reverse_iterator<reverse_iterator<_OutIter> > > 113 __copy_impl(reverse_iterator<reverse_iterator<_InIter> > __first, 114 reverse_iterator<reverse_iterator<_Sent> > __last, 115 reverse_iterator<reverse_iterator<_OutIter> > __result) { 116 auto __ret = std::__copy(__first.base().base(), __last.base().base(), __result.base().base()); 117 return std::make_pair(reverse_iterator<reverse_iterator<_InIter> >(reverse_iterator<_InIter>(__ret.first)), 118 reverse_iterator<reverse_iterator<_OutIter> >(reverse_iterator<_OutIter>(__ret.second))); 119 } 120 121 template <class _InputIterator, class _OutputIterator> 122 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17 123 _OutputIterator 124 copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) { 125 return std::__copy(__first, __last, __result).second; 126 } 127 128 _LIBCPP_END_NAMESPACE_STD 129 130 #endif // _LIBCPP___ALGORITHM_COPY_H 131