Re: zero-alloc cache (was Re: [v3] Fix PR libstdc++/10276)

["B. Kosnik" <bkoz at nabi dot net>]

Jerry.

I'm not quite sure what to do about this. I'm not super happy about
__string. No doubt, you are not pleased with this either. This seems
mighty hacky: the iword/pword stuff seems less so, since these are
reserved slots.

I'm trying to come up with an external allocator, so that you can just do

string<char, char_traits<char>, __extern_alloc> for this stuff.

I think that would be better.

I'll work on this today, and let you know where I am tonight. If this
cannot be resolved, I'm going to suggest that we temporarily back out
the locale cache from 3.3.0 until this has been satisfactorily resolved.
I'm sure this is a big bummer to you, and it is to me as well. The other
speed improvements are still in 3.3.0 though, so it won't be quite as
dire as 3.2.x. Thoughts?

I'm also having second thoughts about this approach to locale caching in
general. I've implemented __has_cache/__use_cache and while it's not as fast
as the __locale_cache code as present, it's still on par with 2.95 and
it seems like a better way to go.

Awful lot of "I's" in the above text. Your honest feedback is appreciated.

Also, perhaps this has been confused in the past: can you make sure that
3.3 check-ins pass "make check-abi" before checking in, or explicitly
note that on the patch? If this is unclear, please let me know how the
docs can be improved to better reflect reality. As I pointed out, there
is still work to be done in check-abi. 

-benjamin