max_element.h 1.9 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_MAX_ELEMENT_H
  9. #define _LIBCPP___ALGORITHM_MAX_ELEMENT_H
  10. #include <__algorithm/comp.h>
  11. #include <__algorithm/comp_ref_type.h>
  12. #include <__config>
  13. #include <__iterator/iterator_traits.h>
  14. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  15. # pragma GCC system_header
  16. #endif
  17. _LIBCPP_BEGIN_NAMESPACE_STD
  18. template <class _Compare, class _ForwardIterator>
  19. inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _ForwardIterator
  20. __max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
  21. {
  22. static_assert(__has_forward_iterator_category<_ForwardIterator>::value,
  23. "std::max_element requires a ForwardIterator");
  24. if (__first != __last)
  25. {
  26. _ForwardIterator __i = __first;
  27. while (++__i != __last)
  28. if (__comp(*__first, *__i))
  29. __first = __i;
  30. }
  31. return __first;
  32. }
  33. template <class _ForwardIterator, class _Compare>
  34. _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _ForwardIterator
  35. max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
  36. {
  37. return _VSTD::__max_element<__comp_ref_type<_Compare> >(__first, __last, __comp);
  38. }
  39. template <class _ForwardIterator>
  40. _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _ForwardIterator
  41. max_element(_ForwardIterator __first, _ForwardIterator __last)
  42. {
  43. return _VSTD::max_element(__first, __last, __less<>());
  44. }
  45. _LIBCPP_END_NAMESPACE_STD
  46. #endif // _LIBCPP___ALGORITHM_MAX_ELEMENT_H