libstdc++-v3/testsuite/20_util/shared_ptr/cons/deduction.cc

   1 // Copyright (C) 2017-2020 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 3, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-options "-std=gnu++17" }
  19 // { dg-do compile { target c++17 } }
  20
  21 #include <memory>
  22
  23 template<typename T, typename U> struct require_same;
  24 template<typename T> struct require_same<T, T> { using type = void; };
  25
  26 template<typename T, typename U>
  27   typename require_same<T, U>::type
  28   check_type(U&) { }
  29
  30 void
  31 test01()
  32 {
  33   std::shared_ptr<long> s;
  34   std::shared_ptr s2 = s;
  35   check_type<std::shared_ptr<long>>(s2);
  36
  37   std::weak_ptr<long> w;
  38   std::shared_ptr s3(w);
  39   check_type<std::shared_ptr<long>>(s3);
  40
  41   struct D { void operator()(double*) { } };
  42   std::unique_ptr<double, D> u;
  43   std::shared_ptr s4 = std::move(u);
  44   check_type<std::shared_ptr<double>>(s4);
  45 }