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
//     pair<iterator,iterator>             equal_range(const K& x);        //
17
//     C++14
18
// template<typename K>
19
//     pair<const_iterator,const_iterator> equal_range(const K& x) const;  //
20
//     C++14
21

22
#include <cassert>
23
#include <set>
24
#include <utility>
25

26
struct Comp {
27
  using is_transparent = void;
28

29
  bool operator()(const std::pair<int, int> &lhs,
30
                  const std::pair<int, int> &rhs) const {
31
    return lhs < rhs;
32
  }
33

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

38
  bool operator()(int lhs, const std::pair<int, int> &rhs) const {
39
    return lhs < rhs.first;
40
  }
41
};
42

43
int main(int, char**) {
44
  std::multiset<std::pair<int, int>, Comp> s{{2, 1}, {1, 1}, {1, 1}, {1, 1}, {2, 2}};
45

46
  auto er = s.equal_range(1);
47
  long nels = 0;
48

49
  for (auto it = er.first; it != er.second; it++) {
50
    assert(it->first == 1);
51
    nels++;
52
  }
53

54
  assert(nels == 3);
55

56
  return 0;
57
}
58