[boost] Re: how to avoid inclusions?

From: Gennaro Prota (gennaro_prota_at_[hidden])
Date: 2003-03-07 14:09:35

On Fri, 7 Mar 2003 18:17:56 +0100, Pavol Droba <droba_at_[hidden]>
wrote:

>I wanted to do something else:
>
>	template <class T> struct trait_class
>   {
>   ....
>   }
>
>   template <class T> struct trait_class<std::vector<T> >
>   {
>   ....
>   }
>
>without #include <vector>
>
>Is this possible?

Practically speaking, no. At least not in a portable, conforming way.
You can (under certain limitations) provide specializations like

 class A { };
 namespace std { template<> class numeric_limits<A> {}; }

but you can't otherwise add declarations to std. There are several
reasons for this limitation.

AFAIK the committee discussed the possibility to provide fwd versions
of standard headers other than <iosfwd> but decided not to do so.

Genny.