John Maddock wrote:
Eric Niebler wrote:
the RegexTraits concept doesn't have toupper() and tolower() functions. I suggest adding them.
Right, but format_perl isn't part of TR1, so this is all in the realms of vendor-specific extensions. I added some *optional* extra members to the traits class to deal with this: the code detects at compile time whether the member are there, and uses them if they are, otherwise uses some sensible defaults.
Ah. I didn't know that format_perl didn't make the cut. But it's still a problem for RegexTraits::value(), format_default ("$1") and format_sed ("\\1"). To be honest, I find the need for the hacks you describe above to be a bit distasteful. Any vendor who wants format_perl-like behavior will route around the damage in the RegexTraits concept. A better (?) design might have to been to go whole-hog with locales and facets, and define some standard regex traits facets that basic_regex<> and match_results<> can query for at runtime. Eg.: If a regex-trait version-2 facet isn't installed, try for version-1, then defer to the ctype and collate facets, etc. And the traits doesn't need to be part of the basic_regex<> type (it isn't in xpressive). C-compatibility could have been maintained by providing a ctype facet that is implemented in terms of the global C locale. The whole RegexTraits concept and version tags seem like wheel reinvention to me. Just thinking out loud, -- Eric Niebler Boost Consulting www.boost-consulting.com