libcxx/test/std/containers/unord/unord.map/compare.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 // <unordered_map>
  10
  11 // template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
  12 //           class Alloc = allocator<pair<const Key, T>>>
  13 // class unordered_map
  14
  15 // https://llvm.org/PR16538
  16 // https://llvm.org/PR16549
  17
  18 #include <unordered_map>
  19 #include <cassert>
  20
  21 #include "test_macros.h"
  22
  23 struct Key {
  24   template <typename T> Key(const T&) {}
  25   bool operator== (const Key&) const { return true; }
  26 };
  27
  28 namespace std
  29 {
  30     template <>
  31     struct hash<Key>
  32     {
  33         std::size_t operator()(Key const &) const {return 0;}
  34     };
  35 }
  36
  37 int main(int, char**)
  38 {
  39     typedef std::unordered_map<Key, int> MapT;
  40     typedef MapT::iterator Iter;
  41     MapT map;
  42     Iter it = map.find(Key(0));
  43     assert(it == map.end());
  44     std::pair<Iter, bool> result = map.insert(std::make_pair(Key(0), 42));
  45     assert(result.second);
  46     assert(result.first->second == 42);
  47
  48   return 0;
  49 }