#if vs. #ifdef

[Glenn Chambers]

Akim Demaille <akim at epita dot fr> writes:

> #ifdef and #ifndef are banished from Autoconf, 
> use only #if and#if !.

Interesting trivium: unless I mis-remember, the variant
of the C compiler used on Bell Lab's "Plan 9" operating
system deprecates '#if' and provides only "#ifdef" and 
"#ifndef".

To paraphrase the wording of the famous Unix kernel comment,

"You are not expected to care."