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

   1 // { dg-do compile { target c++11 } }
   2
   3 // Copyright (C) 2010-2020 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10 //
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 #include <utility>
  21
  22 template <class T>
  23   struct C
  24   {
  25     T t_;
  26
  27     C() { }
  28
  29     template <class U,
  30               class = typename std::enable_if
  31                     <
  32                         !std::is_lvalue_reference<U>::value
  33                     >::type>
  34       C(U&& u) : t_(std::forward<T>(std::move(u).get())) { }
  35
  36     C(C&& c) : t_(std::forward<T>(c.t_)) { }
  37   };
  38
  39 template <class T>
  40   struct Derived
  41   : C<T>
  42   {
  43     Derived() { }
  44     Derived(Derived&& d) : C<T>(std::forward<C<T>>(d)) { }
  45   };
  46
  47 // http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2951.html
  48 // Test E.
  49 int main()
  50 {
  51   Derived<int> d;
  52   Derived<int> d2(std::move(d));
  53 }