llvm-project

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
// UNSUPPORTED: c++03, c++11
10

11
// <set>
12

13
// class multiset
14

15
// template<typename K>
16
//     size_type count(const K& x) const;        // C++14
17

18
#include <cassert>
19
#include <set>
20
#include <utility>
21

22
struct Comp {
23
  using is_transparent = void;
24

25
  bool operator()(const std::pair<int, int> &lhs,
26
                  const std::pair<int, int> &rhs) const {
27
    return lhs < rhs;
28
  }
29

30
  bool operator()(const std::pair<int, int> &lhs, int rhs) const {
31
    return lhs.first < rhs;
32
  }
33

34
  bool operator()(int lhs, const std::pair<int, int> &rhs) const {
35
    return lhs < rhs.first;
36
  }
37
};
38

39
int main(int, char**) {
40
  std::multiset<std::pair<int, int>, Comp> s{{2, 1}, {1, 1}, {1, 1}, {1, 1}, {2, 2}};
41

42
  auto cnt = s.count(1);
43
  assert(cnt == 3);
44

45
  return 0;
46
}
47