Hi Christian, > Hmm, I would say *usually* it is a const reference.-- But eventually it is > not, like in my case or in the case of std::auto_ptr. In C++, a copy constructor is a const reference. > Of course you could say this isn't a copy constructor because it doesn't take a const reference. It's not a copy constructor. > But I think it is anyway because it still has the semantic of a copy operation. Regardless, it's not a copy constructor. > Anyway, I need to have a constructor taking a non-const reference which g++ > doesn't allow. You can implement similar facilities like auto_ptr for your class to have the behavior you are inquiring about. > And I still don't know why g++ is acting this way here and how to work around it. On this particular issue, g++ is complying with ISO 14882. VC7 is not. More information in The Design and Evolution of C++: http://www.amazon.com/gp/product/0201543303/ I don't recall if the particular point you raised is covered. I believe it (copy constructor being a const reference) has to do with catastrophic slicing if it were not a const, and infinite recursion if it were not a reference. Sincerely, --Eljay
