even?

/*
 *  call-seq:
 *     fix.even? -> true or false
 *
 *  Returns <code>true</code> if <i>fix</i> is an even number.
 */

static VALUE
fix_even_p(VALUE num)
{
    if (num & 2) {
        return Qfalse;
    }
    return Qtrue;
}