Re: [boost] Question about optimizations in Boost.Regex

Sam Jiang wrote:

Hi All

I'm just wondering; what kind of optimizations does the regex library come with? i.e if I was to say ^(string1|string2|string3), does it result in same performance as using ^string[123]?

No not currently - actually I don't know of any Perl-Regex libraries that do that at present (but may well be wrong). Most of the optimisations relate to: * Skipping over text that can't possibly match in a small tight loop when searching large texts. * Pruning the search tree as aggressively as possible, to avoid the Perl Regex O(N!) worst case behaviour where possible. HTH, John.