libcxx/test/std/containers/associative/set/count_transparent.pass.cpp

   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 //        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::set<std::pair<int, int>, Comp> s{{2, 1}, {1, 2}, {1, 3}, {1, 4}, {2, 2}};
  41
  42   auto cnt = s.count(1);
  43   assert(cnt == 3);
  44
  45   return 0;
  46 }