Bad error message.

[Martin v. Loewis]

> But there is body for method A::f()!
> It seems that g++ have to say that there is no method A::g().

Thanks for your bug report. This problem is hard to correct, since the
error message originates from the linker. From the linker's point of
view, the analysis

undefined reference to `A::f(void)'

is correct: there really is no reference to A::f in the object files
(go check it yourself). That does not mean there is no implementation
for that function - it only means that the implementation had not been
generated into an object file.

Regards,
Martin