My favorite is similar thing, but in C++ and much more confusing:

  class Bar {};
  
  class Foo {
  public:
  	Foo(const Bar &c) { }
  	void method() { }
  };
  
  int main() {
  	Foo foo(Bar());
  	foo.method();
  	return 0;
  }

"foo.method();" doesn't compile because:

  error: request for member ‘method’ in ‘foo’, which is of non-class type ‘Foo(Bar (*)())’

That's right: "foo" is a declared function that returns instance of Foo and takes one argument - a function that returns instance of Bar :) But when you add additional parentheses in a line above:

  Foo foo((Bar()));

then "foo" is an instance of Foo created by passing a new instance of Bar to its constructor, which is more like what you'd expect by reading the code, and the code compiles. Fun!