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Comment by msla | Hacker News Reader

From my own recollection, the construction

    (void) var;

for unused variables is specifically to silence certain versions of lint which would otherwise complain.

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Nowadays it silences -Wunused-perameter. I'm not a fan as it just adds nonfunctional clutter only needed to appease a tool. The tools are supposed to work on our behalf, not against.

We can also silence -Wunused-perameter by omitting the parameter name in the prototype. No clutter, I'm personally fairly happy with this solution. (Note: the declaration in the header can sill name the parameter, it won't bring the warning back.)

That's only in C++. As far as I know in C you need to name all parameters (although maybe that rule has been relaxed in newer versions of C.)

C23 finally relaxes that rule:

https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2510.pdf

(although some C compilers already allowed it in non-pedantic mode)

I much prefer being warned about unused variables and explicitely having to silence those warnings on a case by case basis though - especially when refactoring (one option is to use a wrapper macro MAYBE_UNUSED(bla) macro, or GCC's __attribute__((unused)) or the C++ [[unused]], or the C23 [[maybe_unused]].

But of all those options, "(void)bla;" might actually be the least clutter (and at the same time the most compatible).

I agree that (void)bla is desirably clear, pithy and unambiguous. And I like something like this if I'm dealing with functions with more than a couple unused parameters:

    static void unused_(int x, ...) { (void)x; }
    #define unused(...) unused_(0, __VA_ARGS__)

This way you can just have one `unused(foo,bar,baz,quux);` line at the top of the function listing all unused parameters.

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