Definition of __USE_MISC?

[Zack Weinberg]

On Thu, Oct 5, 2017 at 2:07 AM, Sebastian Huber
<sebastian.huber@embedded-brains.de> wrote:
> according to the comment in features.h we have:
>
> __USE_MISC        Define things from 4.3BSD or System V Unix.

This was the historic definition, but I believe nowadays __USE_MISC is
just "anything that's not part of an official standard but that we
want to support and make visible by default."  We don't have a
formalized way of deciding whether something belongs under __USE_MISC
or __USE_GNU, but  "this is visible by default on other POSIXy
operating systems" is certainly a strong argument for __USE_MISC.

zw