Re: [Boost-users] [mpl] Hierarchy Generation

From: Scott Meyers (usenet_at_[hidden])
Date: 2008-02-28 01:06:58

Steven Watanabe wrote:
> template<class Sequence>
> struct MakeFeatures {
>     typedef Features<typename copy<Sequence, back_inserter<vector0<> > 
>  >::type> type;
> };

I'm trying to understand the code you posted, but I'm having trouble, probably 
because I'm missing some basic concepts.  I hope people here won't mind helping 
me with something I'm sure is basic:  why do we need to make a copy of Sequence 
here?  I've tried replacing the above typedef with

   typedef Features<Sequence> type;

and everything breaks, so it's clear that the copy is there for a reason, but 
what is it?

Thanks,

Scott