xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/max_element.h (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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   static_assert(
27       __has_forward_iterator_category<_ForwardIterator>::value, "std::max_element requires a ForwardIterator");
28   if (__first != __last) {
29     _ForwardIterator __i = __first;
30     while (++__i != __last)
31       if (__comp(*__first, *__i))
32         __first = __i;
33   }
34   return __first;
35 }
36 
37 template <class _ForwardIterator, class _Compare>
38 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _ForwardIterator
39 max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp) {
40   return std::__max_element<__comp_ref_type<_Compare> >(__first, __last, __comp);
41 }
42 
43 template <class _ForwardIterator>
44 _LIBCPP_NODISCARD inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _ForwardIterator
45 max_element(_ForwardIterator __first, _ForwardIterator __last) {
46   return std::max_element(__first, __last, __less<>());
47 }
48 
49 _LIBCPP_END_NAMESPACE_STD
50 
51 #endif // _LIBCPP___ALGORITHM_MAX_ELEMENT_H
52