You can also use a single regexp with all alternatives and \G and the g flag but without the c flag. Then you can decide which alternative mached by checking the definedness of $1 and other match variables.
I sometimes use that idiom instead of many regexps with a gc flag. A nice example is the glob_to_re function in cgrep (snapshot) (which is btw an improved version of my cgrep: Egrep clone with function name display).
A simpler example is in Re: Logic trouble parsing a formatted text file into hashes of hashes (of hashes, etc.).
