Thanks for the explanation Arkadiy. I had the impression this was probably a
problem of stuff not been implemented yet. However since mpl documentation
talks about vector and push_back I thought it was there...
What I'm trying to do is make a variant that is a superset of another
variant. For that, I make an initial mpl sequence with the types of the
first variant and create it. Then I make a second list with the extra types
of the second variant. I would then like to create the second variant
passing the joint list of the first types sequence and second types
sequence. That is why I wanted to use joint_view. Then I thought I would
just push_back each of the second variant types to the first types sequence
but that failed too. Finally I am doing an insert at the end (essentially a
push_back but not quite).
Thanks again
-delfin
-----Original Message-----
From: boost-users-bounces@lists.boost.org
[mailto:boost-users-bounces@lists.boost.org] On Behalf Of Arkadiy Vertleyb
Sent: Monday, July 19, 2004 5:51 PM
To: boost-users@lists.boost.org
Subject: [Boost-users] Re: Mpl problem
"Delfin Rojas"
I am having a problem with the mpl library and I wonder if someone could help me with it. Basically I am trying to get a joint_view of two mpl::vector types and I get an error message on mpl/clear.hpp saying
clear_traits< Tag > ::template algorithm< Sequence >
base class undefined.
I tried including several of the mpl hpp files, the ones that seemed could have something to do with this problem but that didn't help. I also get a similar problem trying to use mpl::push_back. In this case I get
push_back_traits< Tag > ::template algorithm< Sequence,T >
Base class undefined.
On the other hand mpl::push_front and mpl::insert compile beautifully.
The error messages you are getting basically say: "This algorithm is undefined for this type of sequence." I never used joint_view, but the push_back is currently not defined for the mpl::vector. AFAIK, this is going to be corrected in the next version of Boost (which is currently being put together). Also, if you are trying to use push_back in combination with, say, fold, this can be replaced with push_front in combination with fold_backward. HTH, Arkadiy _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users