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

From: Larry Evans (cppljevans_at_[hidden])
Date: 2007-12-06 12:26:29

On 12/05/07 21:23, Joel de Guzman wrote:
> Larry Evans wrote:
[snip]
>> 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.
Thanks for the feedback.
However, I've thought about it some more and I think maybe the
original variant with fusion::pair's as the template arguments
would work as well and would avoid the duplication of the
tag (variant::which() and variant_taggged:tag()).