Semantic/CEDET is now part of Emacs and does a little bit of that job. I haven't explored the all the features beyond the smart "find tag" (semantic-ia-jump) in

Semantic/CEDET is now part of Emacs and does a little bit of that job. I haven't explored the all the features beyond the smart "find tag" (semantic-ia-jump) in C++ feature, though, so I don't know if it may meet your expectations.