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// Copyright (C) 2008-2022 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING3. If not see
// <http://www.gnu.org/licenses/>.
// { dg-do run { target c++11 } }
#include <sstream>
#include <string>
#include <testsuite_hooks.h>
void
test01()
{
int i = 1742;
std::ostringstream() << i;
std::string result ("1742");
int i2;
std::istringstream(result) >> i2;
VERIFY (i == i2);
}
struct X { bool as_rvalue; };
void operator>>(std::istream&, X& x) { x.as_rvalue = false; }
void operator>>(std::istream&, X&& x) { x.as_rvalue = true; }
// LWG 2328 Rvalue stream extraction should use perfect forwarding
void
test02()
{
X x;
std::istringstream is;
auto&& ref1 = (std::move(is) >> x);
VERIFY( &ref1 == &is );
VERIFY( x.as_rvalue == false );
auto&& ref2 = (std::move(is) >> std::move(x));
VERIFY( &ref2 == &is );
VERIFY( x.as_rvalue == true );
char arr[2];
#if __cplusplus <= 201703L
std::istringstream("x") >> &arr[0];
#endif
std::istringstream("x") >> arr;
VERIFY( std::string(arr) == "x" );
}
// LWG 1203 More useful rvalue stream insertion
void
test03()
{
int i = 1203;
std::string result = (std::ostringstream() << "i = " << i).str();
VERIFY( result == "i = 1203" );
std::ostringstream os;
std::ostringstream&& ros = std::move(os) << result;
VERIFY( &ros == &os );
VERIFY( ros.str() == result );
std::stringstream ss;
std::stringstream&& rss = std::move(ss) << result;
VERIFY( &rss == &ss );
VERIFY( rss.str() == result );
std::istringstream is("first second third");
std::istringstream&& ris = std::move(is) >> result;
VERIFY( &ris == &is );
VERIFY( result == "first" );
std::stringstream ss2("fourth fifth sixth");
std::stringstream&& rss2 = std::move(ss2) >> result;
VERIFY( &rss2 == &ss2 );
VERIFY( result == "fourth" );
}
struct A { friend void operator<<(std::ios_base&, A) { } };
struct O : private std::ios_base { friend void operator<<(O&, int) { } };
template<typename Ostream, typename T, typename = void>
struct is_insertable
: std::false_type
{ };
template<typename> using void_t = void;
template<typename Ostream, typename T>
using insert_result
= decltype(std::declval<Ostream>() << std::declval<const T&>());
template<typename Ostream, typename T>
struct is_insertable<Ostream, T, void_t<insert_result<Ostream, T>>>
: std::true_type
{ };
// LWG 1203 negative tests
void
test04()
{
static_assert( is_insertable<std::ios_base&, A>::value,
"valid using the friend operator<<" );
static_assert( !is_insertable<std::ios_base&&, A>::value,
"ill-formed because ios_base is not derived from ios_base" );
static_assert( is_insertable<O&, int>::value,
"valid using the friend operator<<" );
static_assert( !is_insertable<O&&, int>::value,
"ill-formed because O is not publicly derived from ios_base" );
}
int
main()
{
test01();
test02();
test03();
test04();
}
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