The API supports creating "scratch views," which might be able to mimic this behavior when paired with a sublime mousemap, but I haven't really seen a reason to recreate the behavior of command+r (then again, I don't use C/C++ ).
I thought this sounded funny since programmers usually find it should be the other way around. I.E. replacing functions that require clicking with just typing. Most programmers are adverse to being "forced" to use a mouse and prefer not having to remove their hands from their keyboard.
If you both feel so strongly about the need for a tree of functions, consider posting a ticket at sublimetext.userecho.com
I'm pretty sure this has already been suggested, in that case, just vote for it.