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
  19 #include <utility>
  20 #include <type_traits>
  21 #include <cassert>
  22
  23 #include "test_macros.h"
  24 #include "archetypes.h"
  25
  26 int main(int, char**)
  27 {
  28     {
  29         typedef std::pair<float, short*> P;
  30         P p;
  31         assert(p.first == 0.0f);
  32         assert(p.second == nullptr);
  33     }
  34 #if TEST_STD_VER >= 11
  35     {
  36         typedef std::pair<float, short*> P;
  37         constexpr P p;
  38         static_assert(p.first == 0.0f, "");
  39         static_assert(p.second == nullptr, "");
  40     }
  41     {
  42         using NoDefault = ImplicitTypes::NoDefault;
  43         using P = std::pair<int, NoDefault>;
  44         static_assert(!std::is_default_constructible<P>::value, "");
  45         using P2 = std::pair<NoDefault, int>;
  46         static_assert(!std::is_default_constructible<P2>::value, "");
  47     }
  48     {
  49         struct Base { };
  50         struct Derived : Base { protected: Derived() = default; };
  51         static_assert(!std::is_default_constructible<std::pair<Derived, int> >::value, "");
  52     }
  53 #endif
  54
  55   return 0;
  56 }