[boost] Re: Re: [mpl] Lambda problems (was: rebind<> bad;template template good)

From: David B. Held (dheld_at_[hidden])
Date: 2002-10-08 02:01:48

"Aleksey Gurtovoy" <agurtovoy_at_[hidden]> wrote in message
news:4034600A4760D411B8720001031D84FB010964A8_at_postoffice.office.meta...
> [...]
> Hhm, how about this one:
>
>     template< typename Policy >
>     struct ownership_policy
>     {
>         typedef Policy type;
>         typedef ownership_policy_tag policy_category;
>     };
>
>     template< typename T >
>     struct ref_counted
>         : ownership_policy< ref_counted<T> >
>     {
>         // ...
>     };

Well, that seems obvious enough, but I thought that the fact that the type
typedef used the name of the template is what allowed you to rebind it
without a rebind template.  But now that I think of it, that would mean you
have a template typedef, which is magical indeed.  So I guess I don't
understand how the type field works, and how you get a concrete class
to rebind in lambda (without a rebind template, of course).

Dave