Date: Mon, 3 Mar 2014 16:19:40 +0100
From: "J. Hannken-Illjes" <hann...@eis.cs.tu-bs.de>
On Mar 3, 2014, at 4:11 PM, Taylor R Campbell
<campbell+netbsd-tech-k...@mumble.net> wrote:
> That is exactly what I was going for, except with a typed pointer
> instead of a void pointer.
Please explain in more detail why you prefer a typed pointer over a void
pointer for opaque data. What is the benefit?
If I pass in the wrong thing, then with a typed pointer, the compiler
will warn; with a void pointer, it won't. E.g., consider:
while (vfs_vnode_iterator_next(vi, &vp)) {
...
/* Skip to the next one. */
if (!vfs_vnode_iterator_next(vp, &nvp))
break;
...
}
If vfs_vnode_iterator_next takes a void *, then the compiler will be
happy with this and there's a nontrivial chance that this won't have
any obvious adverse effects for a while. If vfs_vnode_iterator_next
takes a struct vnode_iterator *, then the compiler will promptly
inform me that I failed to mind my p's and i's.
