[libstdc++ PATCH] Implement observer_ptr

[Ed Smith-Rowland]

On 05/01/2015 05:01 PM, Jonathan Wakely wrote:
> On 01/05/15 16:37 +0300, Ville Voutilainen wrote:
>> Tested on Linux-x64.
>>
>>    Implement observer_ptr.
>
> Thanks! Committed with some minor formatting changes.
>
> I've also committed this to add feature-test macros and update the
> docs. Tested powerpc64le-linux, committed to trunk.
>
>
I pretty sure we're supposed to add the macro for *all* the headers that 
got enable_if.

I actually went ahead and did this on 222713.

2015-05-02  Edward Smith-Rowland  <3dw4rd@verizon.net>

     * include/experimental/deque: Add feature-test macro.
     * include/experimental/forward_list: Ditto.
     * include/experimental/list: Ditto.
     * include/experimental/map: Ditto.
     * include/experimental/set: Ditto.
     * include/experimental/string: Ditto.
     * include/experimental/unordered_map: Ditto.
     * include/experimental/unordered_set: Ditto.