I'm no sure if "autohinting" is correct word but I can explain
for example when I write
std::
I want to see the list of available things there, and same for "." and "->" , I hope that is possible.
You can bind .
and >
with semantic-complete-self-insert
command, that will try to show list of possible completions. Although I don't know, is it possible out of box to bind it to ::
sequence (although, it should be possible with some amount of emacs lisp code)
code browsing, refactoring, auto completion in Emacs
Not sure if this is what you are looking for, but it looks related. I think Etags might be what you are looking for.