------- Comment #3 from phresnel at gmail dot com 2010-07-07 06:29 ------- (In reply to comment #1) > (In reply to comment #0) > > > > undefined reference to `vtable for IFoo' > > Suggestions: > > * Ensure that no (pure) member function of `IFoo' became unintentionally > > non-pure because of a missing or deleted `= 0' > > While I think adding a note would be helpful, the suggestion above is > ridiculous. It certainly shouldn't be the first suggestion.
Of course this was just a quick scratch, but stating it's ridiculous is unnecessarily offending, i.e. ridiculous in itself. > The answer is to > ensure the first, non-inline virtual function is defined. That's it. In my humble opinion, no it's not the answer, at least not in my, and I guess in many people's cases. I did not want to define it, but wanted to have a purely virtual function, without definition. Again, the wording is just a quick scratch, but your "answer which is it" is not necessarily the right solution either. > Suggestions about "unintentionally becoming non-pure" would cause more > confusion than they would help. Well, it can be rephrased. Maybe something like "Did you intend to make it a pure virtual function? Add `= 0' then. Otherwise, ensure to define the function." would be the better solution. > > However, the error comes from the linker, so there's nothing gcc can do about > it when compiling. > Okay, my fail to not know that ld bugs don't go here. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44841
