libcxx/test/std/utilities/utility/pairs/pairs.pair/swap.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 // <utility>
  10
  11 // template <class T1, class T2> struct pair
  12
  13 // void swap(pair& p);
  14
  15 #include <utility>
  16 #include <cassert>
  17
  18 #include "test_macros.h"
  19
  20 struct S {
  21     int i;
  22     TEST_CONSTEXPR_CXX20 S() : i(0) {}
  23     TEST_CONSTEXPR_CXX20 S(int j) : i(j) {}
  24     TEST_CONSTEXPR_CXX20 bool operator==(int x) const { return i == x; }
  25 };
  26
  27 TEST_CONSTEXPR_CXX20 bool test() {
  28   {
  29     typedef std::pair<int, short> P1;
  30     P1 p1(3, static_cast<short>(4));
  31     P1 p2(5, static_cast<short>(6));
  32     p1.swap(p2);
  33     assert(p1.first == 5);
  34     assert(p1.second == 6);
  35     assert(p2.first == 3);
  36     assert(p2.second == 4);
  37   }
  38   {
  39     typedef std::pair<int, S> P1;
  40     P1 p1(3, S(4));
  41     P1 p2(5, S(6));
  42     p1.swap(p2);
  43     assert(p1.first == 5);
  44     assert(p1.second == 6);
  45     assert(p2.first == 3);
  46     assert(p2.second == 4);
  47   }
  48   return true;
  49 }
  50
  51 int main(int, char**) {
  52   test();
  53 #if TEST_STD_VER >= 20
  54   static_assert(test());
  55 #endif
  56
  57   return 0;
  58 }