libcxx/test/std/utilities/utility/pairs/pairs.pair/ctor.default.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 // explicit(see-below) constexpr pair();
  14
  15 // NOTE: The SFINAE on the default constructor is tested in
  16 //       default-sfinae.pass.cpp
  17
  18 #include <utility>
  19 #include <type_traits>
  20 #include <cassert>
  21
  22 #include "test_macros.h"
  23 #include "archetypes.h"
  24
  25 int main(int, char**) {
  26   {
  27     typedef std::pair<float, short*> P;
  28     P p;
  29     assert(p.first == 0.0f);
  30     assert(p.second == nullptr);
  31   }
  32 #if TEST_STD_VER >= 11
  33   {
  34     typedef std::pair<float, short*> P;
  35     constexpr P p;
  36     static_assert(p.first == 0.0f, "");
  37     static_assert(p.second == nullptr, "");
  38   }
  39   {
  40     using NoDefault = ImplicitTypes::NoDefault;
  41     using P         = std::pair<int, NoDefault>;
  42     static_assert(!std::is_default_constructible<P>::value, "");
  43     using P2 = std::pair<NoDefault, int>;
  44     static_assert(!std::is_default_constructible<P2>::value, "");
  45   }
  46   {
  47     struct Base {};
  48     struct Derived : Base {
  49     protected:
  50       Derived() = default;
  51     };
  52     static_assert(!std::is_default_constructible<std::pair<Derived, int> >::value, "");
  53   }
  54 #endif
  55
  56   return 0;
  57 }