------- Comment #10 from erh+gcc at nimenees dot com 2010-03-08 16:35 ------- (In reply to comment #8) > > The code that calls the function also *compiles* cleanly, and only the link > > fails. > > No, the code calling it does not compile cleanly if there's no previous > declaration. > It only compiles cleanly if there's an overload that is similar enough that it > can be called via conversion.
If you're maintaining existing code there's a good chance that there will be a similar enough overload. > Do you really write overloads that are so similar, and then declare them in > separate headers? I never said anything about separate headers. You don't need separate headers, you just need to be a bit forgetful about what needs to be changed in a single header. > Don't do that. Even ignoring potential ambiguities, it's asking for problems > if the declarations aren't in a single header. > > But I doubt you really have code like that, so I don't find your argument > convincing. Actually, yes I DID have code like that, although it wasn't intended to be that way. What happened was that I rewrote a function to use "const char *" instead of "char *", and forgot to remove the old one. However, that was a rare occurrence; most of the cases it's just changing the function signature w/o many changes to the implementation code. The case that I keep running into all the time is that I convert a bunch of code from "char *" from "const char*", then go update the header to match up with the code, but happen to miss one (or more) prototypes that needed to be changed. The code compiles, Then sometime later, I (or another developer) build some code that uses the library, a link error occurs, and we're sitting there scratching our heads wondering why it's complaining about a function that, at first glance, appears to exist. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43272
