1. I found this in a c++ project.
looking in semantic-analyze-refs.el in defmethod semantic-analyze-refs-impl:
I think the call to:
(semantic-tag-similar-p tag aT :prototype-flag :parent)
is buggy.

I changed it to:
(semantic-tag-similar-p tag aT :prototype-flag :parent :typemodifiers)

and it works.
I'm not sure that what I did is valid to other programming languages
(i.e. type modifiers are not part of implementation if done outside of class declaration)

2. Is there a function that returns a list of available prototypes/implementations, in a minibuffer or something similar?
   it would be useful for browsing virtual functions.