[libcxx] r215740 - Revert "Turn off extern templates for most uses."

[Justin Bogner]

Howard Hinnant <howard.hinnant at gmail.com> writes:
> On Aug 17, 2014, at 9:06 PM, Justin Bogner <mail at justinbogner.com> wrote:
>
>> I really don't think it's worth the cost of insantiating these very
>> fundamental templates in *every single user* to work around a limitation
>> in the memory sanitizer. This is an unreasonable amount of overhead for
>> standard library types.
>
> Always measure.  I’m not saying you’re wrong.  I’m saying you’re
> stating a performance conclusion without measurements (which should
> never be acceptable).

I did measure :) Though, I sent it to llvm-dev and it probably should've
been cfe-dev. Sorry about that.

http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075793.html