libcxx/test/std/containers/associative/multimap/multimap.value_compare/invoke.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 // <map>
  10
  11 // class value_compare
  12
  13 // bool operator()( const value_type& lhs, const value_type& rhs ) const;
  14
  15 #include <map>
  16 #include <cassert>
  17 #include <string>
  18 #include <utility>
  19
  20 template <typename MMap>
  21 struct CallCompMember : MMap::value_compare {
  22     CallCompMember(const typename MMap::value_compare& vc) : MMap::value_compare(vc) {}
  23
  24     typedef typename MMap::value_type value_type;
  25     bool operator()(const value_type& value1, const value_type& value2) const {
  26         return this->comp(value1.first, value2.first);
  27     }
  28 };
  29
  30 int main(int, char**) {
  31     typedef std::multimap<int, std::string> map_type;
  32
  33     map_type m;
  34     map_type::iterator i1 = m.insert(map_type::value_type(1, "abc"));
  35     map_type::iterator i2 = m.insert(map_type::value_type(2, "abc"));
  36
  37     const map_type::value_compare vc = m.value_comp();
  38     CallCompMember<map_type> call_comp = m.value_comp();
  39
  40     assert(vc(*i1, *i2));
  41     assert(call_comp(*i1, *i2));
  42
  43     assert(!vc(*i2, *i1));
  44     assert(!call_comp(*i2, *i1));
  45
  46     return 0;
  47 }