David Abrahams wrote:
Well if we could solve problem #1, the expense of the initial construction becomes a non-issue for my case, because I'd only have to search once. And regardless of all that, often convenience is *way* more important than efficiency.
That said, as long as the match object is immutable, there's little to worry about w.r.t. thread safety.
Here there be dragons. An immutable match object is appealing, but the performance would be problematic. The match object is essentially a std::vector of sub-matches, dynamically allocated because you don't know how many sub-matches there will be until runtime. Often, you want to match the same pattern repeatedly. In that case, you reuse the match object and avoid the extra allocations. Forcing the creation of a new match object each time would be a terrible pessimization. I'm all for ease-of-use, as long as accommodation is made for those who care about speed. -- Eric Niebler Boost Consulting www.boost-consulting.com