class TrueClass
    def if_true
        yield
    end

    def if_false
    end
end

class FalseClass
    def if_true
    end

    def if_false
        yield
    end
end

aBoolean = 1==2
aBoolean.if_true { print “true!” }
                    // invece di
                    //if aBoolean
                    //  print “true!”
                    //end

aBoolean.if_false { print “false!” }
                    // invece di
                    //if !aBoolean
                    //  print “false!”
                    //end