[cfe-commits] [libc++] Switching to 'double underscore' notation for has_feature.

[Howard Hinnant]

On Mar 1, 2012, at 1:18 PM, Jean-Daniel Dupas wrote:

> Hi,
> 
> clang recently gained support for double underscore variant of the features in __has_feature test (the same way attributes support a double underscore variant).
> This change provide a way to safely use __has_feature in system headers without conflicting with potential user defined macros.
> 
> As libc++ headers are system headers, I suggest we switch to using the double underscore variant. 
> A problem I see is that applying this change will break compatibility with older clang version. 
> If this is not an issue, I attached a patch that performs this change.
> 
> Thanks
> 
> -- Jean-Daniel
> 
> 
> 
> <underscore.patch>_______________________________________________

Thanks for creating this patch Jean-Daniel.  I'm going to need to wait a while before I apply it.  Not sure how long, maybe a month.

Howard