libcxx/test/std/utilities/utility/pairs/pair.astuple/get_non_const.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 // template<size_t I, class T1, class T2>
  14 //     typename tuple_element<I, std::pair<T1, T2> >::type&
  15 //     get(pair<T1, T2>&);
  16
  17 #include <utility>
  18 #include <cassert>
  19
  20 #include "test_macros.h"
  21
  22 #if TEST_STD_VER > 11
  23 struct S {
  24    std::pair<int, int> a;
  25    int k;
  26    constexpr S() : a{1,2}, k(std::get<0>(a)) {}
  27    };
  28
  29 constexpr std::pair<int, int> getP () { return { 3, 4 }; }
  30 #endif
  31
  32 int main(int, char**)
  33 {
  34     {
  35         typedef std::pair<int, short> P;
  36         P p(3, static_cast<short>(4));
  37         assert(std::get<0>(p) == 3);
  38         assert(std::get<1>(p) == 4);
  39         std::get<0>(p) = 5;
  40         std::get<1>(p) = 6;
  41         assert(std::get<0>(p) == 5);
  42         assert(std::get<1>(p) == 6);
  43     }
  44
  45 #if TEST_STD_VER > 11
  46     {
  47         static_assert(S().k == 1, "");
  48         static_assert(std::get<1>(getP()) == 4, "");
  49     }
  50 #endif
  51
  52
  53   return 0;
  54 }