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 set
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::set<std::pair<int, int>, Comp> s{{2, 1}, {1, 2}, {1, 3}, {1, 4}, {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