Re: [boost] Re: program_options lib: how to denote return values?

From: Vladimir Prus (ghost_at_[hidden])
Date: 2003-05-26 01:47:10

Chuck Messenger wrote:

> > As for me, I'm a bit unsure about introducing new syntax. In this case,
> > I'm not sure overloading of >> is 100% intuitive --- one can assume that
> > value of "magic" is read from "param" result, for example.
>
> OK, then how about this:
>
>       magic = desc.option<int>("magic|value|magic value for program");
>       val   = desc.option("val||some value with a default", defValue);
>
> etc.  (note that <int> is needed only in the first case, since there is
> no default value from which to infer the type).

That's better. OTOH, it still does not fit well in current scheme. Now, 
everything can be configured using member functions of 'option_descirption' 
class. The 'parameter' function adds some convenience, but in effect just 
calls relevant methods internally.

The syntax above requires very special support.

> If you like, the assignments could even be deferred (although I don't
> see the point of doing that).

Can you clarify what's "deferred"? The above code, as I understand it, would 
only say that option "val" should be stored in variable "val". The actual 
storing will happen after parsing. Or do you have something else in mind?

- Volodya

>
>
>      - Chuck
>
>
> _______________________________________________
> Unsubscribe & other changes:
> http://lists.boost.org/mailman/listinfo.cgi/boost