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//
// Test that ref(ref(x)) does NOT collapse to ref(x)
//
// This irregularity of std::ref is questionable and breaks
// existing Boost code such as proto::make_expr
//
// Copyright 2014 Peter Dimov
//
// Distributed under the Boost Software License, Version 1.0.
// See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt
//
#include <boost/ref.hpp>
#include <boost/core/lightweight_test.hpp>
template<class T> void test( T const & t )
{
{
boost::reference_wrapper< T const > r = boost::ref( t );
BOOST_TEST_EQ( &r.get(), &t );
}
{
boost::reference_wrapper< T const > r = boost::cref( t );
BOOST_TEST_EQ( &r.get(), &t );
}
}
template<class T> void test_nonconst( T & t )
{
{
boost::reference_wrapper< T > r = boost::ref( t );
BOOST_TEST_EQ( &r.get(), &t );
}
{
boost::reference_wrapper< T const > r = boost::cref( t );
BOOST_TEST_EQ( &r.get(), &t );
}
}
int main()
{
int x = 0;
test( x );
test( boost::ref( x ) );
test( boost::cref( x ) );
test_nonconst( x );
{
boost::reference_wrapper< int > r = boost::ref( x );
test_nonconst( r );
}
{
boost::reference_wrapper< int const > r = boost::cref( x );
test_nonconst( r );
}
return boost::report_errors();
}
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