Vector transform function in GL?

[Lewis Yuchan Geer]

Does there exist a function in the graphics library that will take a
coordinate vector, multiply it with the current transform matrix and return
the result?  I have a very strong impression that I have seen such a
function, but for the life of me I can't find it in any of the manuals.  I
know this can be accomplished with feedback -- if the function doesn't
exist, has anyone written one?
Thanks,
Lewis Geer
lewis at castor.wustl.edu