Re: [boost] interest in 'tagged variant'? Useful in non-string spirit parsing.

From: Joel de Guzman (joel_at_[hidden])
Date: 2007-12-05 22:23:48

Larry Evans wrote:
> A recent thread in spirit.general NG suggested to me the need for
> a 'tagged variant' extension to boost::variant in order to emulate
> the tagged-union mentioned in this post in the thread:
> 
> http://article.gmane.org/gmane.comp.parsers.spirit.general/12611
> 
> A prototype of such an extension is available in variant_tagged.zip
> here:
> 
> http://www.boost-consulting.com/vault/index.php?&directory=Data%20Structures
> 
> Use of the variant_tagged could be used whenever non-string processing
> is required in a spirit parser.  Each tag in the using corresponds to
> a token-id and each value associated with that token-id is the attribute
> for that token-id.  This closely emulates the way yacc does it, IIRC, 
> except it just uses a union and the tag is somehow "implicit".
> 
> Is there any interest in using this in spirit or boost in general?

There's definitely interest in Spirit :-)
Thanks for your work on this. Very useful.

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