Unused parameter in c++11

Question

In c++03 and earlier to disable compiler warning about unused parameter I usually use such code:

#define UNUSED(expr) do { (void)(expr); } while (0) 

For example

int main(int argc, char *argv[]) {     UNUSED(argc);     UNUSED(argv);      return 0; } 

But macros are not best practice for c++, so. Does any better solution appear with c++11 standard? I mean can I get rid of macros?

Thanks for all!

Answer 1

You can just omit the parameter names:

int main(int, char *[]) {      return 0; } 

And in the case of main, you can even omit the parameters altogether:

int main() {     // no return implies return 0; } 

See "§ 3.6 Start and Termination" in the C++11 Standard.

Answer 2

There is the <tuple> in C++11, which includes the ready to use std::ignore object, that's allow us to write (very likely without imposing runtime overheads):

void f(int x) {     std::ignore = x; }