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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// <istream>
// template <class Stream, class T>
// Stream&& operator>>(Stream&& is, T&& x);
#include <istream>
#include <sstream>
#include <cassert>
#include "test_macros.h"
template <class CharT>
struct testbuf
: public std::basic_streambuf<CharT>
{
typedef std::basic_string<CharT> string_type;
typedef std::basic_streambuf<CharT> base;
private:
string_type str_;
public:
testbuf() {}
testbuf(const string_type& str)
: str_(str)
{
base::setg(const_cast<CharT*>(str_.data()),
const_cast<CharT*>(str_.data()),
const_cast<CharT*>(str_.data()) + str_.size());
}
CharT* eback() const {return base::eback();}
CharT* gptr() const {return base::gptr();}
CharT* egptr() const {return base::egptr();}
};
struct Int {
int value;
template <class CharT>
friend void operator>>(std::basic_istream<CharT>& is, Int& self) {
is >> self.value;
}
};
struct A { };
bool called = false;
void operator>>(std::istream&, A&&) { called = true; }
int main(int, char**)
{
{
testbuf<char> sb(" 123");
Int i = {0};
std::istream is(&sb);
std::istream&& result = (std::move(is) >> i);
assert(&result == &is);
assert(i.value == 123);
}
{
testbuf<wchar_t> sb(L" 123");
Int i = {0};
std::wistream is(&sb);
std::wistream&& result = (std::move(is) >> i);
assert(&result == &is);
assert(i.value == 123);
}
{
// test perfect forwarding
assert(called == false);
std::istringstream ss;
std::istringstream&& result = (std::move(ss) >> A());
assert(&result == &ss);
assert(called);
}
return 0;
}
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