Re: [Boost-users] Static typing question

From: Joel de Guzman (joel_at_[hidden])
Date: 2007-04-19 18:44:14

Ovanes Markarian wrote:
> Hello all!
> 
> 
> I have a question on static typing. Does someone know or can imagine a way on producing unique
> static types. An example:
> 
> 
> typedef unsigned int    some_type;
> typedef unsigned int    other_type;
> 
> 
> typedef fusion::map< fusion::pair<some_type, std::string>, fusion::pair<other_type, std::string> >
>  my_map;
> 
> my_map   my_map_(fusion::make_pair<some_type>("some_type"),
> fusion::make_pair<other_type>("other_type"));
> 
> 
> at_key<other_type>(my_map) should return "other_type" and not "some_type"

How about using mpl::int_ or something similar? Example:

     template <int ID>
     struct key;

     typedef key<1> tag1;
     typedef key<2> tag2;

actually, you can get by with simple forward declared structs:

    struct tag1;
    struct tag2;

Cheers,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net