C++0x Error: overloading a function with std::shared_ptr to const argument is ambiguous

Question

Suppose I have two unrelated classes A and B. I also have a class Bla that uses boost::shared_ptr like t

Answer 1

http://bytes.com/topic/c/answers/832994-shared_ptr-derived-classes-ambiguitity-overloaded-functions

struct yes_type { char dummy; };
struct no_type { yes_type a; yes_type b; };

template < typename From, typename To >
class is_convertible
{
    private:
        static From* dummy ( void );

        static yes_type check ( To );

        static no_type check ( ... );

    public:

        static bool const value = sizeof( check( *dummy() ) ) == sizeof( yes_type );

}; // is_convertible

An in boost's shared_ptr.h, change the constructor signature to:

template
shared_ptr(shared_ptr const & r,
    typename enable_if::value, void*>::type = 0
    ): px(r.px), pn(r.pn) // never throws
{
}