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

   1 // { dg-do compile }
   2 // { dg-options "-std=gnu++0x" }
   3
   4 // Copyright (C) 2010-2014 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 <list>
  24
  25 template <class T>
  26   struct C
  27   {
  28     T t_;
  29
  30     template <class U,
  31               class = typename std::enable_if
  32                     <
  33                         !std::is_lvalue_reference<U>::value
  34                     >::type>
  35       C(U&& u) : t_(std::forward<T>(std::move(u).get())) {}
  36   };
  37
  38 class A
  39 {
  40   int data_;
  41 public:
  42   explicit
  43   A(int data = 1)
  44   : data_(data) { }
  45
  46   ~A() { data_ = -1; }
  47
  48   void test() const
  49   {
  50     __builtin_abort();
  51   }
  52 };
  53
  54 class Awrap
  55 {
  56   const A& a_;
  57 public:
  58   explicit Awrap(const A& a) : a_(a) {}
  59   const A /* & */ get() const { return a_; }
  60 };
  61
  62 template <class C>
  63   void test(C c)
  64   {
  65     c.t_.test();
  66   }
  67
  68 // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2951.html
  69 // Test C.
  70 int main()
  71 {
  72   std::list<C<const A&> > list;
  73   A a(3);
  74   C<const A&> c((Awrap(a)));
  75   list.push_back(c);
  76   test(c);
  77   test(list.front());
  78 }