[boost] Re: [optional]output

From: Joel de Guzman (joel_at_[hidden])
Date: 2005-03-09 11:20:05

David Abrahams wrote:
> Joel de Guzman <joel_at_[hidden]> writes:
> 
>>Perhaps do as the tuples do?
>>
>>    [123] <- a non-empty optional<int>
>>    []    <- an empty optional<T>
> 
> 
> If you want to be unambiguous, it has to be more like:
> 
>      [hello] <- a non-empty optional<std::string>
>      []      <- a non-empty optional<std::string> (the string is empty)
>      _       <- an empty optional<T>
> 

Nice!

I think the variant needs to follow. What does variant do?

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