Re: Bogus ifdef guard in sys/null.h

[Mindaugas Rasiukevicius <rmind%netbsd.org@localhost>]

Bernd Ernesti <netbsd%lists.veego.de@localhost> wrote:
> 
> > POSIX says that both stddef.h and unistd.h shall provide NULL. This
>                                              ^^^^^
> shall != must
> 
> So not a mandatory requirement.
> 

Apart from "shall" having a slightly stronger notation in English (and
commonly used in standards or legal texts as a synonym of "must"), POSIX
explicitly defines what "shall" means:

        shall

        For an implementation that conforms to POSIX.1-2008, describes a
        feature or behavior that is mandatory. An application can rely on
        the existence of the feature or behavior.

        For an application or user, describes a behavior that is mandatory.

-- 
Mindaugas