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
26struct 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
43int 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(x: 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

source code of libcxx/test/std/containers/associative/multiset/equal_range_transparent.pass.cpp