Ticket #7577: ref_member_from_base.cpp

#include <boost/assert.hpp>

#include <boost/type_traits/remove_reference.hpp>

#include <boost/utility/base_from_member.hpp>

#include <algorithm>
#include <vector>

template< typename Iterator >
struct iterator_something
{
    iterator_something( Iterator const& first, Iterator const& last )
      : _first( first ), _last( last )
    {}

    std::size_t distance()
    {
        return std::distance( _first, _last );
    }

    Iterator _first, _last;
};

template< typename Container >
struct container_something
  : boost::base_from_member< Container >
  , iterator_something<
        typename boost::remove_reference< Container >::type::iterator
    >
{
    typedef boost::base_from_member< Container > container_member;

    explicit container_something( Container& container )
      : boost::base_from_member< Container >( container )
      , iterator_something<
            typename boost::remove_reference< Container >::type::iterator
        >( container_member::member.begin(), container_member::member.end() )
    {}
};

int main()
{
    std::vector< int > v;
    v.push_back( 0 );
    v.push_back( 1 );
    v.push_back( 2 );

    container_something< std::vector< int > > something_copy( v );
    something_copy.distance(); // right

    container_something< std::vector< int >& > something_ref( v );
    something_ref.distance(); // wrong
}