id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
3022,Automatic conversion from Y* to boost::shared_ptr<Y> with std::pair,koelsch@…,Peter Dimov,"The assignment of std::pair<X,Y*> to std::pair<X,boost::shared_ptr<Y> > compiles without warning and implicitly converts a Y* to a boost::shared_ptr<Y>. I guess this has to do with:

template<class T> class shared_ptr
{
...
template<class Ap>
typename boost::detail::sp_enable_if_auto_ptr< Ap, shared_ptr & >::type operator=( Ap r )
...
};

This behavior was witnessed under VC2005, VC2008, and gcc4.0.1.

A minimal program demonstrating an evil consequence of this follows:

int main()
{
    int i = 2;
    boost::shared_ptr<int> j( new int );

    //boost::shared_ptr<int> k = &*j; // does not compile
    //std::pair<int,boost::shared_ptr<int> > v( i, &*j ); // does not compile
    std::pair<int,boost::shared_ptr<int> > v = std::make_pair( i, &*j ); // However, this compiles
    // kabum
}

Regards,

   Tobias",Bugs,closed,,smart_ptr,Boost 1.39.0,Problem,invalid,implicit conversion shared_ptr,