[Boost-users] fusion quesion

Fusion includes a number of binary functions such as join, equal, less, etc. Looking at the code suggests that they just work element by element in sequential order. But what about associative tuples? For example struct account {}; struce amount {}; typedef boost::fusion::set< account, amount

debit;

typedef boost::fusion::set< amount, account

debit2.

clearly the types are meant to be the "same" so I would expect boost::fusion::join(debit, debit2) to function and return one type. I'm thinking it doesn't do that. Any observations/suggestions that any Fusion guru would like to share would be appreciated. Robert Ramey