[boost] Making 'any' visitable

From: Andrei Alexandrescu (andrewalex_at_[hidden])
Date: 2002-04-10 02:31:42

I'd like to propose making 'any' visitable. Without visitation, all
you can do to query the type of any is to do it explicitly, which is
awkward and error-prone.

With visitation, one can add processing to any that is nicely
decoupled. (By the way, due to the nature of 'any', it seems like only
acyclic visitation will do - the classic GoF visitor won't work.)

So, in a nutshell - do you guys think it's a good idea?

Andrei