http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54075
--- Comment #9 from François Dumont <fdumont at gcc dot gnu.org> 2012-07-24 20:15:10 UTC --- I confirm that the reserve method is broken. I had correctly handle the size hint that can be given through the hashtable constructor, I set _M_rehash_policy._M_prev_resize to 0 just to avoid the container to be shrink until it reaches the targetted size. The same thing should be done in the rehash method that is called from reserve one. I will submit a patch soon. Regarding the shrink on insert calls, well, it can be easily avoided by calling (normally) reserve so I considered that it is better to offer a container with a symetric behavior. I will also I think reconsider the grow factor. During one of my propositions of hashtable redesign the number of empty buckets was a problem for performance. With the current implementation it is not a problem anymore so we could grow a little bit faster.
