struct vs class for a simple token in my d lexer

[Roman D. Boiko]

(Subj.) I'm in doubt which to choose for my case, but this is a 
generic question.

http://forum.dlang.org/post/odcrgqxoldrktdtarskf@forum.dlang.org

Cross-posting here. I would appreciate any feedback. (Whether to 
reply in this or that thread is up to you.) Thanks