Unused variable preference

[Jeff Mitchell]

Do we have a preference for whether to comment out an unused variable  
in the code:

void
SomeClass::SomeFunction( void used, void /*notused*/ )
{
}

or whether to use Q_UNUSED():

void
SomeClass::SomeFunction( void used, void notused )
{
     Q_UNUSED( notused );
}

--Jeff