Michael Marcin skrev:
Thorsten Ottosen wrote:
I'll try to investigate this.
I appreciate it. If you have things you'd like me to try out I can compile them and send you the mixed assembly output.
One thing I noticed is that it seems to fail to eliminate the return value copy of the void_ptr_iterator::base call. Accessing iter_ directly (unfortunately) produces much better code but still not the best.
I have tried playing a little with your example, eg. using operator[] instead. To my surprise, I could not eliminate the overhead with vc8 (/Ox /Og). Thus the iterator wrapping seems to pay some penalty. This is quite strange IMO. Perhaps it is not optimal for iterator_adaptor to return base() by const&. Perhaps I'm doing something wrong. At any rate, I would have assumed iteration to be optimal. I'll have to use some more time on this ... but thanks for pointing out the problem. -Thorsten