[boost] Re: Re: Re: Re: Re: relational tableasanSTLcontainer--anyinterest?

From: Arkadiy Vertleyb (vertleyb_at_[hidden])
Date: 2002-11-01 22:54:41

"Joel de Guzman" <djowel_at_[hidden]> wrote in message
news:01ce01c28215$891a1ff0$0100a8c0_at_kim...

> BTW, if you wish to have the tup.field syntax, you might find
> inspiration in boost.spirit closures. Example syntax:
>
>     struct my_tuple : tuple_fields<my_tuple, std::string, int, int>
>     {
>         member1 name;
>         member2 id;
>         member3 age;
>     };
>
> Then:
>
>     my_tuple tup;
>     std::cout << tup.name << std::endl;
>
> see http://spirit.sourceforge.net/index.php?doc=docs/v1_5/closures.html

Here you explicitly define your fields, which makes impossible something
like projection or cross-product.

As far as boost::tuple is concerned, I need some time to consider pros and
cons.

By the way, what are the objections against our current approach?  One, as I
understand, the need for macro.  Another is that boost::tuple is already
widely used throughout the library.  Anything else?

Just to re-iterate, we currently define a class for every column.  This
class contains a placeholder for the value.  The name of this class serves
as the column name.  Columns (classes) get combined in a typelist, which is
passed to the tuple, which inherits from all of them.  Static_cast is used
to access individual fields.

Regards,

Arkadiy