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

From: Chuck Messenger (chuckm_at_[hidden])
Date: 2003-05-26 11:05:01

Vladimir Prus wrote:
> Chuck Messenger wrote:
>>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);
>>
> 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.

I would think it would be worth extra complication in the library code, 
if it simplified the user interface.

>>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?

OK -- you're right.  Looking again at your library's interface, then 
deferred evaluation is what would happen.

     - Chuck