Re: [Boost-users] [Fusion] fusion::traits::is_sequence <->mpl::is_sequence?

From: Tobias Schwinger (tschwinger_at_[hidden])
Date: 2007-01-19 15:32:12

Sohail Somani wrote:
> -----Original Message-----
> From: boost-users-bounces_at_[hidden] on behalf of Tobias Schwinger
> 
> Sohail Somani wrote:
>  > If I am trying to make a fusion sequence mpl compatible, do I need to
>  > specialize mpl::is_sequence as well? 
> 
> No. mpl::is_sequence just checks whether mpl::begin returns mpl::void_
> (in this case it's not an MPL Sequence).
> 
> --------------
> 
> Thank you for your reply. If I do what you suggest (include 
> intrinsic/mpl), it still doesn't compile. I checked 
> fusion::result_of::begin<myseq>::type was correct but 
> mpl::begin<type>::type is still void_. I'm sure I'm doing something 
> wrong, but I can't figure out what!

I guess you have to make sure that mpl::sequence_tag returns 
fusion::fusion_sequence_tag. An easy way to do it is to add a 'tag' type 
member.

     struct my_seq
     {
         typedef fusion::fusion_sequence_tag tag;
         // ...

Regards,
Tobias