libstdc++-v3/testsuite/27_io/rvalue_streams.cc

   1 // Copyright (C) 2008-2020 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-do run { target c++11 } }
  19
  20 #include <sstream>
  21 #include <string>
  22 #include <testsuite_hooks.h>
  23
  24 void
  25 test01()
  26 {
  27   int i = 1742;
  28   // This usage isn't supported by the current draft.
  29   // std::string result = (std::ostringstream() << i).str();
  30   std::ostringstream() << i;
  31   std::string result ("1742");
  32   int i2;
  33   std::istringstream(result) >> i2;
  34   VERIFY (i == i2);
  35 }
  36
  37 struct X { bool as_rvalue; };
  38
  39 void operator>>(std::istream&, X& x) { x.as_rvalue = false; }
  40 void operator>>(std::istream&, X&& x) { x.as_rvalue = true; }
  41
  42 // LWG 2328 Rvalue stream extraction should use perfect forwarding
  43 void
  44 test02()
  45 {
  46   X x;
  47   std::istringstream is;
  48   auto& ref1 = (std::move(is) >> x);
  49   VERIFY( &ref1 == &is );
  50   VERIFY( x.as_rvalue == false );
  51   auto& ref2 = (std::move(is) >> std::move(x));
  52   VERIFY( &ref2 == &is );
  53   VERIFY( x.as_rvalue == true );
  54
  55   char arr[2];
  56   std::istringstream("x") >> &arr[0];
  57   std::istringstream("x") >> arr;
  58 }
  59
  60 int
  61 main()
  62 {
  63   test01();
  64   test02();
  65   return 0;
  66 }