unique_copy.h 3.5 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_UNIQUE_COPY_H
  9. #define _LIBCPP___ALGORITHM_UNIQUE_COPY_H
  10. #include <__algorithm/comp.h>
  11. #include <__config>
  12. #include <__iterator/iterator_traits.h>
  13. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  14. # pragma GCC system_header
  15. #endif
  16. _LIBCPP_BEGIN_NAMESPACE_STD
  17. template <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
  18. _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
  19. __unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
  20. input_iterator_tag, output_iterator_tag)
  21. {
  22. if (__first != __last)
  23. {
  24. typename iterator_traits<_InputIterator>::value_type __t(*__first);
  25. *__result = __t;
  26. ++__result;
  27. while (++__first != __last)
  28. {
  29. if (!__pred(__t, *__first))
  30. {
  31. __t = *__first;
  32. *__result = __t;
  33. ++__result;
  34. }
  35. }
  36. }
  37. return __result;
  38. }
  39. template <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
  40. _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
  41. __unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
  42. forward_iterator_tag, output_iterator_tag)
  43. {
  44. if (__first != __last)
  45. {
  46. _ForwardIterator __i = __first;
  47. *__result = *__i;
  48. ++__result;
  49. while (++__first != __last)
  50. {
  51. if (!__pred(*__i, *__first))
  52. {
  53. *__result = *__first;
  54. ++__result;
  55. __i = __first;
  56. }
  57. }
  58. }
  59. return __result;
  60. }
  61. template <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
  62. _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
  63. __unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
  64. input_iterator_tag, forward_iterator_tag)
  65. {
  66. if (__first != __last)
  67. {
  68. *__result = *__first;
  69. while (++__first != __last)
  70. if (!__pred(*__result, *__first))
  71. *++__result = *__first;
  72. ++__result;
  73. }
  74. return __result;
  75. }
  76. template <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
  77. inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  78. _OutputIterator
  79. unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
  80. {
  81. return _VSTD::__unique_copy<_BinaryPredicate&>(__first, __last, __result, __pred,
  82. typename iterator_traits<_InputIterator>::iterator_category(),
  83. typename iterator_traits<_OutputIterator>::iterator_category());
  84. }
  85. template <class _InputIterator, class _OutputIterator>
  86. inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  87. _OutputIterator
  88. unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
  89. {
  90. typedef typename iterator_traits<_InputIterator>::value_type __v;
  91. return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
  92. }
  93. _LIBCPP_END_NAMESPACE_STD
  94. #endif // _LIBCPP___ALGORITHM_UNIQUE_COPY_H