False positive with --warn-unreachable: TypedDict may be empty #7743
Description
Hi,
I believe there is a false positive related to empty TypedDicts with total=False.
Using --warn-unreachable:
from typing_extensions import TypedDict
class A(TypedDict, total=False):
...
class B(TypedDict, total=False):
x: int
a: A = {}
b: B = {}
if not a:
print('a is empty')
if not b:
print('b is empty') # error: Statement is unreachableUsing Python 3.7.4, tested with both mypy 0.740 and mypy master.