# File unused.hxx¶

Defines

UNUSED(x)

Mark a function parameter as unused in the function body

For GCC, expands to

UNUSED_x __attribute__((unused))


Macro taken from http://stackoverflow.com/q/7090998/2043465

This will add the “unused” attribute to parameters in function signatures, telling the compiler that we know the parameter isn’t used. This should cut down on false positives when using -Wunused-parameters.

Additionally, this macro will also rename the parameter so that if it is accidentally used, the compiler will throw an error.

A better way to do this might be to detect how to silence the warning in configure and use that in the macro instead.

Example

void someFunction(int UNUSED(x)) {};


MAYBE_UNUSED(x)

Mark a function parameter as possibly unused in the function body

Unlike UNUSED, this has to go around the type as well:

MAYBE_UNUSED(int foo);