[Patch]: Corrected patch for stl_tree.h to improve performance and memory usage

[Benjamin Kosnik]

>Again, sweet work.  I think you have nailed all of the performance
>issues raised.  If you ever answered the first time I asked in regards
>to your std::list improvements back around Feb 12, I'm sorry I missed
>it. 

Ditto! This stuff looks good.

>First, do you[/Nortel --- where you posted from last month] have an
>assignment for GCC on file with the FSF?  Based on the informal
>10-line rule, your work appears to be beyond a simple bug/performance
>fix.  Opinions on this point by other library maintainers?

I don't know off hand. I could go either way with it.

It would probably be best to get an assignment though.

Gawain, Phil Edwards will know the current status of gcc/libstdc++
assignments. I know that contributions from Nortel (or their
subsidiaries) have been accepted in the past, and that in general,
Nortel seems quite friendly to free software. Perhaps they have a
blanket company assignment already in place for all of gcc? I've cc'd
Anthony Green on this email, who might know more details.

>Next, since this change hits a file included in application code and
>the libray ABI, we would need to consider when to apply it.  If we
>strongly believe that the new implementation satisfies the standard in
>every way (and I believe that you have studied and reported on the
>issues well enough to satisfy me) and only has rare cases where
>performance could ever worsen in practice (I'm sold), then I'd vote
>before the 3.3 release.

You have my full agreement. 

Loren, would you be willing to merge this and the std::list bits posted
previously, when the assignment bits get answered?

-benjamin