[libcxx] r293154 - Use the new __has_feature(cxx_constexpr_string_builtins) for detection of the C-string intrinsics for constexpr support in std::char_traits. Thanks to Richard for the intrisic support.

[Hans Wennborg via cfe-commits]

On Thu, Jan 26, 2017 at 6:08 AM, Marshall Clow <mclow.lists at gmail.com> wrote:
> On Wed, Jan 25, 2017 at 10:58 PM, Marshall Clow via cfe-commits
> <cfe-commits at lists.llvm.org> wrote:
>>
>> Author: marshall
>> Date: Thu Jan 26 00:58:29 2017
>> New Revision: 293154
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=293154&view=rev
>> Log:
>> Use the new __has_feature(cxx_constexpr_string_builtins) for detection of
>> the C-string intrinsics for constexpr support in std::char_traits. Thanks to
>> Richard for the intrisic support.
>>
>> Modified:
>>     libcxx/trunk/include/__config
>>     libcxx/trunk/include/__string
>>
>
> Hans --
>
> This should be merged to the 4.0 branch.
> Thanks!

r293193.

Cheers,
Hans