Re: [boost] Re: Re: more flexible any

From: Douglas Gregor (gregod_at_[hidden])
Date: 2002-09-02 21:24:24

On Monday 02 September 2002 05:25 am, Alexander Nasonov wrote:
> Ok, let it be dynamic_any. Here is only one mirror problem. Three words in
> dynamic_any_cast while all others known (to me) casts consist of two words:
> static_cast, reinterpret_cast, dynamic_cast, any_cast, lexical_cast,
> numeric_cast and so on.

Why is this a problem? I thought that dynamic_any would use the same names as 
any (e.g., any_cast)

> I'd like to get responces about operators == and != for dynamic_any and
> using of std::set<dynamic_any> and std::map<dynamic_any, value_type>. How
> often they were simulated and how successully? Your responces can help to
> understand real need of these features.

any/dynamic_any starts losing its usefulness when we add more requirements on 
the types contained in them. It would, however, be _extremely_ interesting if 
one could extend any/dynamic_any in a way that supported user-defined sets of 
operations on any/dynamic_any objects (e.g., one might want !=, ==, *, and ++ 
defined to make 'any' work on input & forward iterators). Might be able to do 
this by using mixins with virtual functions...

        Doug