<alert comment=<boost newbie"> Xpressive provides a "tips n tricks" to: Compiling a regex (dynamic or static) is more expensive than executing a match or search. If you have the option, prefer to compile a pattern into a basic_regex<> object once and reuse it rather than recreating it over and over. Would it be feasible/advantageous for the regex-related libraries to automagically to "cache" the immediately previous regex compilation? (or provide as an option) I've seen code that had the same regex being compiled inside a loop, which I suppose would really diminish performance. Perhaps this could be detected, and the user/developer "protected from themselves" ... and/or perhaps informed that this is happening? Could there be a "helper" class that somehow or other allowed the last "n" regexes to be cached? (btw .... what is the plural of regex .... regexen? regices?) </alert>