[PATCH] D16360: unordered_map: Avoid unnecessary mallocs when no insert occurs

[Duncan P. N. Exon Smith via cfe-commits]

> On 2016-Mar-16, at 15:41, Eric Fiselier <eric at efcs.ca> wrote:
> 
> EricWF accepted this revision.
> EricWF added a comment.
> This revision is now accepted and ready to land.
> 
> LGTM after change in inline comment.
> 
> 
> ================
> Comment at: include/__hash_table:114
> @@ +113,3 @@
> +template <class _Pair, class _Key, class _First, class _Second>
> +struct __can_extract_key<_Pair, _Key, pair<_First, _Second>>
> +    : conditional<is_same<typename remove_const<_First>::type, _Key>::value,
> ----------------
> `>>` needs to be `> >` for C++03.

Since __can_extract_key is only used when !defined(_LIBCPP_CXX03_LANG),
I'll just move it behind an #ifdef (and leave the prettier `>>`).

I'll commit after running the tests with -std=c++03.

> 
> http://reviews.llvm.org/D16360
> 
> 
>