On 1/7/2012 7:06 PM, Dave Abrahams wrote:
The desire of "modern language theorists" is to enable language extension without losing interoperability with the rest of the language, and I think what you can do with constexpr, while very cool, still falls far short of that.
While I agree with all of this, I still think there is a place for a constexpr string-based regex library. One of the shortcomings of xpressive is the need to learn a new syntax to use it. I anticipate that compile time will be a big problem with string-based constexpr metaprogramming. For a string of length N, you'll need to instantiate /at least/ O(N) templates just to get the parse tree. And that's only the first step. With expression templates, you get the parse tree for free, and even so compile times have been a bottleneck. -- Eric Niebler BoostPro Computing http://www.boostpro.com