Datasets:

SwashBuckler001
/

idiombench

class P(Protocol):
    x: float

def f(arg: P) -> None:
    arg.x = 0.42

class C:
    x: int

c = C()
f(c)  # Would typecheck if covariant subtyping
      # of mutable attributes were allowed.
c.x >> 1  # But this fails at runtime

	class P(Protocol):
	x: float

	def f(arg: P) -> None:
	arg.x = 0.42

	class C:
	x: int

	c = C()
	f(c) # Would typecheck if covariant subtyping
	# of mutable attributes were allowed.
	c.x >> 1 # But this fails at runtime