Jeff King <peff@xxxxxxxx> wrote:
[...]
> A void pointer is guaranteed to be able to hold any type of pointer
> (either char * or struct foo * or whatever). The declaration of malloc
> indicates a return of void *. On a platform where it matters, the
> compiler generates code so that
> struct foo *bar = malloc(100);
> converts the void * pointer into the correct size (in the same way that
> assigning between differently sized integers works).
Right.
> This breaks down with variadic functions, which have no typing
> information. So doing this:
> execl("foo", "bar", my_struct_foo);
> doesn't give the compiler a chance to do the implicit cast and you get
> subtle breakage (in the same way that you would if you passed a long to
> a variadic function expecting a short).
It just passes 3 "void *"'s, and casts back. What is so strange?
--
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