Re: NetBSD and _POSIX_C_SOURCE

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Sat, 4 May 2019 12:15:08 +0100
    From:        Sad Clouds <cryintothebluesky%gmail.com@localhost>
    Message-ID:  <20190504121508.a491df867c439cd122ce32b7%googlemail.com@localhost>

  | So if I'm not mistaken, then defining only _POSIX_C_SOURCE=200809L
  | explicitly hides _NETBSD_SOURCE,

Correct.

  | hence if I want POSIX + all NetBSD
  | extensions then it looks like I need to define both?

Or just define nothing, or just _NETBSD_SOURCE ... that is essentially
a superset of POSIX (or all the POSIX that we have anyway - you can't
make more appear by magic by defining _POSIX_C_SOURCE).

Usually defining one (or more) of the standards specific versions is
useful only when you want to limit the program to use only what the
standard says exists, as you want to be able to move it to other systems
that also support that standard, and for that to work, you need to avoid
local extensions.

If there something the you're not getting without defining any of these
things which _POSIX_C_SOURCE=200809L is providing for you?

kre