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 // <map>
12 
13 // class map
14 
15 // template<typename K>
16 //         pair<iterator,iterator>             equal_range(const K& x); // C++14
17 // template<typename K>
18 //         pair<const_iterator,const_iterator> equal_range(const K& x) const;
19 //         // C++14
20 
21 #include <cassert>
22 #include <map>
23 #include <utility>
24 
25 struct Comp {
26   using is_transparent = void;
27 
28   bool operator()(const std::pair<int, int> &lhs,
29                   const std::pair<int, int> &rhs) const {
30     return lhs < rhs;
31   }
32 
33   bool operator()(const std::pair<int, int> &lhs, int rhs) const {
34     return lhs.first < rhs;
35   }
36 
37   bool operator()(int lhs, const std::pair<int, int> &rhs) const {
38     return lhs < rhs.first;
39   }
40 };
41 
42 int main(int, char**) {
43   std::map<std::pair<int, int>, int, Comp> s{
44       {{2, 1}, 1}, {{1, 2}, 2}, {{1, 3}, 3}, {{1, 4}, 4}, {{2, 2}, 5}};
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.first == 1);
51     nels++;
52   }
53 
54   assert(nels == 3);
55 
56   return 0;
57 }
58