Little conveniences

[Greg Hudson]

On Sat, 2009-10-03 at 18:59 -0400, Danilo Almeida wrote:
> Wrt the out pointer argument casting issues, you can do something like this:
> 
>   #define k5alloc(Size, PointerToPointer) \
>       ( !((*(PointerToPointer)) = calloc(Size, 1)) ? ENOMEM : 0 )
[...]
> ret = k5alloc(sizeof(foo), &foo);

Yeah, I was careful to say that it's not possible to write as a C
function; it would be possible as a macro.  (Even, as you illustrate, a
macro using each of the arguments only once.)  I'm a little reluctant to
introduce a construction which can only be defined as a macro, but if
people think it's worth that price to keep the order consistent, I'll
switch it around.