Do an OR in Switch-Case in C++

How would you do this in C++? For example I'm trying to trigger a program exit both if the user presses ESC or 'q' or 'Q'.

I've tried looking for it, but I found no syntax for it in C++. I know how to do it with if-else, but is it possible with switch - case? Of course I can just make a function and call it from two separate case, but is there a way to do it just by combined case statement?

For example that's what I'm looking for (of course not working):

void keyboard( unsigned char key, int x, int y )
{
    switch( key )
    {
        case ( 27 || 'q' || 'Q' ):
            exit( 0 );
            break;

        case 'a': ...

                case 'b': ...
    }
}