set_union.h 2.6 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_UNION_H
  9. #define _LIBCPP___ALGORITHM_SET_UNION_H
  10. #include <__algorithm/comp.h>
  11. #include <__algorithm/comp_ref_type.h>
  12. #include <__algorithm/copy.h>
  13. #include <__config>
  14. #include <__iterator/iterator_traits.h>
  15. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  16. # pragma GCC system_header
  17. #endif
  18. _LIBCPP_BEGIN_NAMESPACE_STD
  19. template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
  20. _LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
  21. __set_union(_InputIterator1 __first1, _InputIterator1 __last1,
  22. _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
  23. {
  24. for (; __first1 != __last1; ++__result)
  25. {
  26. if (__first2 == __last2)
  27. return _VSTD::copy(__first1, __last1, __result);
  28. if (__comp(*__first2, *__first1))
  29. {
  30. *__result = *__first2;
  31. ++__first2;
  32. }
  33. else
  34. {
  35. if (!__comp(*__first1, *__first2))
  36. ++__first2;
  37. *__result = *__first1;
  38. ++__first1;
  39. }
  40. }
  41. return _VSTD::copy(__first2, __last2, __result);
  42. }
  43. template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
  44. inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  45. _OutputIterator
  46. set_union(_InputIterator1 __first1, _InputIterator1 __last1,
  47. _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
  48. {
  49. typedef typename __comp_ref_type<_Compare>::type _Comp_ref;
  50. return _VSTD::__set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
  51. }
  52. template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
  53. inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  54. _OutputIterator
  55. set_union(_InputIterator1 __first1, _InputIterator1 __last1,
  56. _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
  57. {
  58. return _VSTD::set_union(__first1, __last1, __first2, __last2, __result,
  59. __less<typename iterator_traits<_InputIterator1>::value_type,
  60. typename iterator_traits<_InputIterator2>::value_type>());
  61. }
  62. _LIBCPP_END_NAMESPACE_STD
  63. #endif // _LIBCPP___ALGORITHM_SET_UNION_H