How to suppress "unused parameter" warnings in C?

Question

For instance: Bool NullFunc(const struct timespec *when, const char *who) { return TRUE; }In C++ I was able to put a `/*...*/` comment around the parameters. But not in C of course, where it gives me the error `error: parameter name omitted`.

Answer 1

In C, the most portable way to do that is to call the parameter, but cast the value to void.

Bool NullFunc(const struct timespec *when, const char *who) {

(void)when;

(void)who;

return TRUE;

}

As a side note, in C++17 onward, you can use the [[maybe_unused]] attribute:

bool NullFunc([[maybe_unused]] const struct timespec *when,

[[maybe_unused]] const char *who) {

return TRUE;

}