5 Nov
2017
5 Nov
'17
11:06 a.m.
Paul Ruizendaal <pnr(a)planet.nl> wrote:
I’m trying to understand the origins of void pointers
in C. I think
they first appeared formally in the C89 spec, but may have existed in
earlier compilers.
void was added after the publication of the first edition of K&R, in
the V7 time frame. The 4.x compilers had support for void pointers and
functions returning void. Also added around the same time was structure
assignment and the ability to pass and return structs by value (although
this was little used).
In the 4BSD era there was caddr_t, which I think was
used for pretty
much the same purposes.
Only for kernel code. I am pretty sure caddr_t wasn't used in user-land code.
HTH,
Arnold