libcxx/test/std/utilities/utility/pairs/pairs.pair/ctor.move.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 // UNSUPPORTED: c++03
  10
  11 // <utility>
  12
  13 // template <class T1, class T2> struct pair
  14
  15 // pair(pair&&) = default;
  16
  17 #include <cassert>
  18 #include <memory>
  19 #include <type_traits>
  20 #include <utility>
  21
  22 #include "test_macros.h"
  23
  24 struct Dummy {
  25   Dummy(Dummy const&) = delete;
  26   Dummy(Dummy &&) = default;
  27 };
  28
  29 struct NotCopyOrMoveConstructible {
  30   NotCopyOrMoveConstructible() = default;
  31   NotCopyOrMoveConstructible(NotCopyOrMoveConstructible const&) = delete;
  32   NotCopyOrMoveConstructible(NotCopyOrMoveConstructible&&) = delete;
  33 };
  34
  35 int main(int, char**)
  36 {
  37     {
  38         typedef std::pair<int, short> P1;
  39         static_assert(std::is_move_constructible<P1>::value, "");
  40         P1 p1(3, static_cast<short>(4));
  41         P1 p2 = std::move(p1);
  42         assert(p2.first == 3);
  43         assert(p2.second == 4);
  44     }
  45     {
  46         using P = std::pair<Dummy, int>;
  47         static_assert(!std::is_copy_constructible<P>::value, "");
  48         static_assert(std::is_move_constructible<P>::value, "");
  49     }
  50     {
  51         // When constructing a pair containing a reference, we only bind the
  52         // reference, so it doesn't matter whether the type is or isn't
  53         // copy/move constructible.
  54         {
  55             using P = std::pair<NotCopyOrMoveConstructible&, int>;
  56             static_assert(std::is_move_constructible<P>::value, "");
  57
  58             NotCopyOrMoveConstructible obj;
  59             P p2{obj, 3};
  60             P p1(std::move(p2));
  61             assert(&p1.first == &obj);
  62             assert(&p2.first == &obj);
  63         }
  64         {
  65             using P = std::pair<NotCopyOrMoveConstructible&&, int>;
  66             static_assert(std::is_move_constructible<P>::value, "");
  67
  68             NotCopyOrMoveConstructible obj;
  69             P p2{std::move(obj), 3};
  70             P p1(std::move(p2));
  71             assert(&p1.first == &obj);
  72             assert(&p2.first == &obj);
  73         }
  74     }
  75
  76     return 0;
  77 }