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 _InIter, class _OutIter,
60           __enable_if_t<is_same<typename remove_const<__iter_value_type<_InIter> >::type, __iter_value_type<_OutIter> >::value
61                       && __is_cpp17_contiguous_iterator<_InIter>::value
62                       && __is_cpp17_contiguous_iterator<_OutIter>::value
63                       && is_trivially_copy_assignable<__iter_value_type<_OutIter> >::value, int> = 0>
64 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
65 pair<reverse_iterator<_InIter>, reverse_iterator<_OutIter> >
66 __copy_impl(reverse_iterator<_InIter> __first,
67             reverse_iterator<_InIter> __last,
68             reverse_iterator<_OutIter> __result) {
69   auto __first_base = std::__unwrap_iter(__first.base());
70   auto __last_base = std::__unwrap_iter(__last.base());
71   auto __result_base = std::__unwrap_iter(__result.base());
72   auto __result_first = __result_base - (__first_base - __last_base);
73   std::__copy_impl(__last_base, __first_base, __result_first);
74   return std::make_pair(__last, reverse_iterator<_OutIter>(std::__rewrap_iter(__result.base(), __result_first)));
75 }
76 
77 template <class _InIter, class _Sent, class _OutIter,
78           __enable_if_t<!(is_copy_constructible<_InIter>::value
79                        && is_copy_constructible<_Sent>::value
80                        && is_copy_constructible<_OutIter>::value), int> = 0 >
81 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
82 pair<_InIter, _OutIter> __copy(_InIter __first, _Sent __last, _OutIter __result) {
83   return std::__copy_impl(std::move(__first), std::move(__last), std::move(__result));
84 }
85 
86 template <class _InIter, class _Sent, class _OutIter,
87           __enable_if_t<is_copy_constructible<_InIter>::value
88                      && is_copy_constructible<_Sent>::value
89                      && is_copy_constructible<_OutIter>::value, int> = 0>
90 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
91 pair<_InIter, _OutIter>
92 __copy(_InIter __first, _Sent __last, _OutIter __result) {
93   auto __ret = std::__copy_impl(std::__unwrap_iter(__first), std::__unwrap_iter(__last), std::__unwrap_iter(__result));
94   return std::make_pair(std::__rewrap_iter(__first, __ret.first), std::__rewrap_iter(__result, __ret.second));
95 }
96 
97 template <class _InputIterator, class _OutputIterator>
98 inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
99 _OutputIterator
100 copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
101   return std::__copy(__first, __last, __result).second;
102 }
103 
104 _LIBCPP_END_NAMESPACE_STD
105 
106 #endif // _LIBCPP___ALGORITHM_COPY_H
107