libcxx/include/__algorithm/max_element.h

   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
   9 #ifndef _LIBCPP___ALGORITHM_MAX_ELEMENT_H
  10 #define _LIBCPP___ALGORITHM_MAX_ELEMENT_H
  11
  12 #include <__algorithm/comp.h>
  13 #include <__algorithm/comp_ref_type.h>
  14 #include <__config>
  15 #include <__iterator/iterator_traits.h>
  16
  17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  18 #  pragma GCC system_header
  19 #endif
  20
  21 _LIBCPP_BEGIN_NAMESPACE_STD
  22
  23 template <class _Compare, class _ForwardIterator>
  24 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _ForwardIterator
  25 __max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
  26 {
  27     static_assert(__has_forward_iterator_category<_ForwardIterator>::value,
  28         "std::max_element requires a ForwardIterator");
  29     if (__first != __last)
  30     {
  31         _ForwardIterator __i = __first;
  32         while (++__i != __last)
  33             if (__comp(*__first, *__i))
  34                 __first = __i;
  35     }
  36     return __first;
  37 }
  38
  39 template <class _ForwardIterator, class _Compare>
  40 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _ForwardIterator
  41 max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
  42 {
  43     return _VSTD::__max_element<__comp_ref_type<_Compare> >(__first, __last, __comp);
  44 }
  45
  46
  47 template <class _ForwardIterator>
  48 _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _ForwardIterator
  49 max_element(_ForwardIterator __first, _ForwardIterator __last)
  50 {
  51     return _VSTD::max_element(__first, __last, __less<>());
  52 }
  53
  54 _LIBCPP_END_NAMESPACE_STD
  55
  56 #endif // _LIBCPP___ALGORITHM_MAX_ELEMENT_H