Re: "A diagram of C23 basic types"

scott@slp53.sl.home (Scott Lurndal) writes:

Tim Rentsch <tr.17687@z991.linuxsc.com> writes:

scott@slp53.sl.home (Scott Lurndal) writes:

bart <bc@freeuk.com> writes:

[...]

So it is not true that you need include stddef.h, nor obvious
that that is where NULL is defined, if you are used to having it
available indirectly.

>
Indeed, and it is well documented.
>
For example, in the POSIX description for the string functions
you'll find the following statement:
>
    [CX] Inclusion of the <string.h> header may also make visible
         all symbols from <stddef.h>.  [Option End]
>
This is true for a number of POSIX headers, include those you
enumerate above.
>
[CX] marks a POSIX extension to ISO C.

>
How strange.  I don't know why anyone would ever want either to
rely on or to take advantage of this property.

>
Some existing unix implementations at the time the standard was adopted
had that behavior and the committee was not willing to break existing
implementations.

You mean the POSIX standard, yes?  The C standard does not permit
<string.h> to include <stddef.h>.

--
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */