set_intersection.h 3.4 KB

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  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_SET_INTERSECTION_H
  9. #define _LIBCPP___ALGORITHM_SET_INTERSECTION_H
  10. #include <__algorithm/comp.h>
  11. #include <__algorithm/comp_ref_type.h>
  12. #include <__algorithm/iterator_operations.h>
  13. #include <__config>
  14. #include <__iterator/iterator_traits.h>
  15. #include <__iterator/next.h>
  16. #include <__utility/move.h>
  17. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  18. # pragma GCC system_header
  19. #endif
  20. _LIBCPP_BEGIN_NAMESPACE_STD
  21. template <class _InIter1, class _InIter2, class _OutIter>
  22. struct __set_intersection_result {
  23. _InIter1 __in1_;
  24. _InIter2 __in2_;
  25. _OutIter __out_;
  26. // need a constructor as C++03 aggregate init is hard
  27. _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  28. __set_intersection_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
  29. : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
  30. };
  31. template <class _AlgPolicy, class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
  32. _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __set_intersection_result<_InIter1, _InIter2, _OutIter>
  33. __set_intersection(
  34. _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
  35. while (__first1 != __last1 && __first2 != __last2) {
  36. if (__comp(*__first1, *__first2))
  37. ++__first1;
  38. else {
  39. if (!__comp(*__first2, *__first1)) {
  40. *__result = *__first1;
  41. ++__result;
  42. ++__first1;
  43. }
  44. ++__first2;
  45. }
  46. }
  47. return __set_intersection_result<_InIter1, _InIter2, _OutIter>(
  48. _IterOps<_AlgPolicy>::next(std::move(__first1), std::move(__last1)),
  49. _IterOps<_AlgPolicy>::next(std::move(__first2), std::move(__last2)),
  50. std::move(__result));
  51. }
  52. template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
  53. inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_intersection(
  54. _InputIterator1 __first1,
  55. _InputIterator1 __last1,
  56. _InputIterator2 __first2,
  57. _InputIterator2 __last2,
  58. _OutputIterator __result,
  59. _Compare __comp) {
  60. return std::__set_intersection<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
  61. std::move(__first1),
  62. std::move(__last1),
  63. std::move(__first2),
  64. std::move(__last2),
  65. std::move(__result),
  66. __comp)
  67. .__out_;
  68. }
  69. template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
  70. inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_intersection(
  71. _InputIterator1 __first1,
  72. _InputIterator1 __last1,
  73. _InputIterator2 __first2,
  74. _InputIterator2 __last2,
  75. _OutputIterator __result) {
  76. return std::__set_intersection<_ClassicAlgPolicy>(
  77. std::move(__first1),
  78. std::move(__last1),
  79. std::move(__first2),
  80. std::move(__last2),
  81. std::move(__result),
  82. __less<>())
  83. .__out_;
  84. }
  85. _LIBCPP_END_NAMESPACE_STD
  86. #endif // _LIBCPP___ALGORITHM_SET_INTERSECTION_H