copy.h 4.5 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106
  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. #ifndef _LIBCPP___ALGORITHM_COPY_H
  9. #define _LIBCPP___ALGORITHM_COPY_H
  10. #include <__algorithm/unwrap_iter.h>
  11. #include <__config>
  12. #include <__iterator/iterator_traits.h>
  13. #include <__iterator/reverse_iterator.h>
  14. #include <__utility/move.h>
  15. #include <__utility/pair.h>
  16. #include <cstring>
  17. #include <type_traits>
  18. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  19. # pragma GCC system_header
  20. #endif
  21. _LIBCPP_BEGIN_NAMESPACE_STD
  22. // copy
  23. template <class _InIter, class _Sent, class _OutIter>
  24. inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
  25. pair<_InIter, _OutIter> __copy_impl(_InIter __first, _Sent __last, _OutIter __result) {
  26. while (__first != __last) {
  27. *__result = *__first;
  28. ++__first;
  29. ++__result;
  30. }
  31. return pair<_InIter, _OutIter>(std::move(__first), std::move(__result));
  32. }
  33. template <class _InValueT,
  34. class _OutValueT,
  35. class = __enable_if_t<is_same<typename remove_const<_InValueT>::type, _OutValueT>::value
  36. && is_trivially_copy_assignable<_OutValueT>::value> >
  37. inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
  38. pair<_InValueT*, _OutValueT*> __copy_impl(_InValueT* __first, _InValueT* __last, _OutValueT* __result) {
  39. if (__libcpp_is_constant_evaluated()
  40. // TODO: Remove this once GCC supports __builtin_memmove during constant evaluation
  41. #ifndef _LIBCPP_COMPILER_GCC
  42. && !is_trivially_copyable<_InValueT>::value
  43. #endif
  44. )
  45. return std::__copy_impl<_InValueT*, _InValueT*, _OutValueT*>(__first, __last, __result);
  46. const size_t __n = static_cast<size_t>(__last - __first);
  47. if (__n > 0)
  48. ::__builtin_memmove(__result, __first, __n * sizeof(_OutValueT));
  49. return std::make_pair(__first + __n, __result + __n);
  50. }
  51. template <class _InIter, class _OutIter,
  52. __enable_if_t<is_same<typename remove_const<__iter_value_type<_InIter> >::type, __iter_value_type<_OutIter> >::value
  53. && __is_cpp17_contiguous_iterator<_InIter>::value
  54. && __is_cpp17_contiguous_iterator<_OutIter>::value
  55. && is_trivially_copy_assignable<__iter_value_type<_OutIter> >::value, int> = 0>
  56. inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
  57. pair<reverse_iterator<_InIter>, reverse_iterator<_OutIter> >
  58. __copy_impl(reverse_iterator<_InIter> __first,
  59. reverse_iterator<_InIter> __last,
  60. reverse_iterator<_OutIter> __result) {
  61. auto __first_base = std::__unwrap_iter(__first.base());
  62. auto __last_base = std::__unwrap_iter(__last.base());
  63. auto __result_base = std::__unwrap_iter(__result.base());
  64. auto __result_first = __result_base - (__first_base - __last_base);
  65. std::__copy_impl(__last_base, __first_base, __result_first);
  66. return std::make_pair(__last, reverse_iterator<_OutIter>(std::__rewrap_iter(__result.base(), __result_first)));
  67. }
  68. template <class _InIter, class _Sent, class _OutIter,
  69. __enable_if_t<!(is_copy_constructible<_InIter>::value
  70. && is_copy_constructible<_Sent>::value
  71. && is_copy_constructible<_OutIter>::value), int> = 0 >
  72. inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
  73. pair<_InIter, _OutIter> __copy(_InIter __first, _Sent __last, _OutIter __result) {
  74. return std::__copy_impl(std::move(__first), std::move(__last), std::move(__result));
  75. }
  76. template <class _InIter, class _Sent, class _OutIter,
  77. __enable_if_t<is_copy_constructible<_InIter>::value
  78. && is_copy_constructible<_Sent>::value
  79. && is_copy_constructible<_OutIter>::value, int> = 0>
  80. inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
  81. pair<_InIter, _OutIter>
  82. __copy(_InIter __first, _Sent __last, _OutIter __result) {
  83. auto __ret = std::__copy_impl(std::__unwrap_iter(__first), std::__unwrap_iter(__last), std::__unwrap_iter(__result));
  84. return std::make_pair(std::__rewrap_iter(__first, __ret.first), std::__rewrap_iter(__result, __ret.second));
  85. }
  86. template <class _InputIterator, class _OutputIterator>
  87. inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  88. _OutputIterator
  89. copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result) {
  90. return std::__copy(__first, __last, __result).second;
  91. }
  92. _LIBCPP_END_NAMESPACE_STD
  93. #endif // _LIBCPP___ALGORITHM_COPY_H