gratuitous gcc warnings: unused function arguments?

[Tim Kientzle]

Robert Watson <rwatson at freebsd.org> complained that:
> 
>>At some point in the relatively recent past, we began to generate
>>warnings for unused arguments in function definitions.  ....
>>
>>int
>>main(int argc, char *argv[])
>>{
>>
>>        if (argc != 1)ut
>>                usage();
>>
>>	dostuff();
>>}

Giorgos Keramidas suggested:
> 
> %      (void)argv;

I first saw this idiom for marking unused
arguments over 10 years ago and have used
it extensively since then.  Very portable;
highly recommended.

Tim