I wouldn't really say they are optional. The two do different things. (int) foo (or (int)(foo)) is a c-style cast. int(foo) isn't a cast. Instead it invokes the

I wouldn't really say they are optional. The two do different things. (int) foo (or (int)(foo)) is a c-style cast. int(foo) isn't a cast. Instead it invokes the int constructor with the argument foo.