From: Larry Evans (cppljevans_at_[hidden])
Date: 2007-12-05 17:19:28
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?