Pavol Droba <droba@topmail.sk> writes:
On Tue, Apr 06, 2004 at 08:33:56PM -0400, David Abrahams wrote:
"Eric Niebler" <eric@boost-consulting.com> writes:
David Abrahams wrote:
Pavol Droba <droba@topmail.sk> writes:
On Tue, Apr 06, 2004 at 02:43:20PM -0400, David Abrahams wrote:
> What would be the advantage? User can write iterator_range > res=regex_maxch(...);
Doesn't the match object get destroyed here, thereby invalidating the iterators?
Not really as far as I know. Iterators are bound to the collection that is being searched, not to the match itself. Therfore, they validity should not be bound the lifetime of them match. They will be copied to the iterarator_range. The match object *is* the collection (of submatches) being searched.
A sub-match is just a glorified pair of iterators. The iterators refer to the sequence being searched, which has a lifetime independent of the match object. There is no risk of iterator invalidation here.
I'm not worried about submatch's iterators over the original input sequence, but about the match_results's iterators over submatches.
These are destroyed and forgotten. That's the idea of the example. If you are interested only in the success/failure of the search operation, or you want to know which part of sequence has been matched, then you don't need full match_results. Those two iterators (contained in the iterator_range) are more then sufficient, and you don't need to pay an extra price implied by match_results.
Maybe I got it wrong, but the discussion before seemed to deal with a problem like this.
Maybe I got it wrong; I want to be able to look at the 2nd submatch when the match succeeded. If all I get is an iterator the whole substring that matched, it's of no use to me. -- Dave Abrahams Boost Consulting www.boost-consulting.com