libstdc++-v3/testsuite/20_util/forward/f_neg.cc

   1 // { dg-do compile }
   2 // { dg-options "-std=gnu++11" }
   3
   4 // Copyright (C) 2010-2015 Free Software Foundation, Inc.
   5 //
   6 // This file is part of the GNU ISO C++ Library.  This library is free
   7 // software; you can redistribute it and/or modify it under the
   8 // terms of the GNU General Public License as published by the
   9 // Free Software Foundation; either version 3, or (at your option)
  10 // any later version.
  11 //
  12 // This library is distributed in the hope that it will be useful,
  13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 // GNU General Public License for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License along
  18 // with this library; see the file COPYING3.  If not see
  19 // <http://www.gnu.org/licenses/>.
  20
  21 // { dg-error "static assertion failed" "" { target *-*-* } 89 }
  22
  23 #include <utility>
  24
  25 template <class T>
  26   struct C
  27   {
  28     T t_;
  29
  30     C() {}
  31
  32     explicit C(const T& t) : t_(t) { }
  33
  34     template <class U,
  35               class = typename std::enable_if
  36                     <
  37                         std::is_convertible<U, T>::value
  38                     >::type>
  39       C(C<U>&& c) : t_(std::forward<T>(c.t_)) { }
  40   };
  41
  42 class B;
  43
  44 class A
  45 {
  46   int data_;
  47
  48   friend class B;
  49 public:
  50   explicit
  51   A(int data = 1)
  52   : data_(data) { }
  53
  54   ~A() { data_ = -1; }
  55
  56   void test() const
  57   {
  58     __builtin_abort();
  59   }
  60 };
  61
  62 class B
  63 {
  64   int data_;
  65 public:
  66   explicit
  67   B(int data = 1)
  68   : data_(data) { }
  69
  70   B(const A& a) : data_(a.data_) { }
  71
  72   B(A&& a) : data_(a.data_) { a.data_ = 100; }
  73
  74   ~B() { data_ = -1; }
  75
  76   void test() const
  77   {
  78     __builtin_abort();
  79   }
  80 };
  81
  82 // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2951.html
  83 // Test F.
  84 int main()
  85 {
  86   A a(3);
  87   C<A> ca(a);
  88   C<const B&> cb(std::move(ca));
  89   cb.t_.test();
  90 }