D-Programming-Language/phobos — pull request #367 by blackwhale (2011-12-12 12:11:04+00:00)
Title: Hopefully final decision on escapes in character sets

As per last known good idea:
- allow escaping of _all_ regex related punctuation [\^$.|?*+(){} inside of character class
- disalowing anything else that is not a known escape sequence