[Patch] Whole regex refactoring and current status

[Paolo Carlini]

Hi,

>> In my humble opinion involving the whole std::bitset container for a
>> syntax option is way overkill.
>
>It's already used for match_flag_type anyway.

Indeed, I noticed it a few days ago, and seemed overkill ;) Really, we already have implementation experience about these flags, eg in iostream, and I dont think we want std::bitset everywhere.

Paolo

Paolo