[boost] [variant] make_variant_over requirement

From: Joel de Guzman (joel_at_[hidden])
Date: 2007-02-17 04:53:41

Hi,

In the variant docs, in the make_variant_over section
(Using a type sequence to specify bounded types), it is
not clear what MPL sequence concept it is referring to.

I was hoping it is a Forward Sequence, but I realized that
when I try to use make_variant_over with a Forward Sequence,
it fails trying to use mpl::clear, which hints that
make_variant_over requires an MPL Extensible Sequence.
This is rather undesirable. Is there a reason why this is so?
Can't we lessen the requirement? The situation makes it not
possible to use mpl views or fusion views for example.

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net