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// <algorithm>
10
11// template<ForwardIterator Iter>
12// requires LessThanComparable<Iter::value_type>
13// Iter
14// max_element(Iter first, Iter last);
15
16#include <algorithm>
17#include <random>
18#include <cassert>
19
20#include "test_macros.h"
21#include "test_iterators.h"
22
23std::mt19937 randomness;
24
25template <class Iter>
26void
27test(Iter first, Iter last)
28{
29 Iter i = std::max_element(first, last);
30 if (first != last)
31 {
32 for (Iter j = first; j != last; ++j)
33 assert(!(*i < *j));
34 }
35 else
36 assert(i == last);
37}
38
39template <class Iter>
40void
41test(int N)
42{
43 int* a = new int[N];
44 for (int i = 0; i < N; ++i)
45 a[i] = i;
46 std::shuffle(first: a, last: a+N, g&: randomness);
47 test(Iter(a), Iter(a+N));
48 delete [] a;
49}
50
51template <class Iter>
52void
53test()
54{
55 test<Iter>(0);
56 test<Iter>(1);
57 test<Iter>(2);
58 test<Iter>(3);
59 test<Iter>(10);
60 test<Iter>(1000);
61}
62
63#if TEST_STD_VER >= 14
64constexpr int il[] = { 2, 4, 6, 8, 7, 5, 3, 1 };
65#endif
66
67void constexpr_test()
68{
69#if TEST_STD_VER >= 14
70 constexpr auto p = std::max_element(il,il+8);
71 static_assert ( *p == 8, "" );
72#endif
73}
74
75int main(int, char**)
76{
77 test<forward_iterator<const int*> >();
78 test<bidirectional_iterator<const int*> >();
79 test<random_access_iterator<const int*> >();
80 test<const int*>();
81
82 constexpr_test ();
83
84 return 0;
85}
86

source code of libcxx/test/std/algorithms/alg.sorting/alg.min.max/max_element.pass.cpp