class Foo

	def main is shared
		s = 'aoeu'
		t = s to String  # .warning. The given expression is already a "String" so the typecast is redundant. You can remove it.

		a = B() to A    # no warning here because casting to a more general type is a legit way to affect type inference
		.compute(a)  # just to use the variable to avoid a warning

		u = 'aoeu' to ?
		t = u to String  # .warning. The given expression is already a "String", but nilable. You can just use "to !".

		u2 = u to String?  # .warning. The given expression is already a "String?" so the typecast is redundant. You can remove it.
		assert u2  # just to use the variable to avoid a warning

		u = t to String?  # .warning. The given expression is already a "String", but not nilable. You can just use "to ?".

	def compute(a as A) is shared
		pass

class A
	pass


class B
	inherits A	
	pass