Enhancement: Added support for metaclasses that support the __getitem__, __setitem__ and __delitem__ magic methods, allowing classes that derive from these metaclasses to be used in index expressions.
Bug Fix: Fixed bug that caused dataclass usage to break in Python 3.6 and older when using the polyfill library.
Enhancement: Added conditional type support for __setitem__ so a value with a type defined by a constrained TypeVar can be assigned to an index expression.
Bug Fix: Fixed bug that caused a crash in the tokenizer when encountering a string literal that is extremely long (>100K in length).
Bug Fix: Fixed bug caused by a variable assignment with a list expression on the RHS that was interpreted temporarily as a type alias declaration. Added more sanity checking on the type of the assigned expression for type aliases.
Bug Fix: Fixed type evaluation bug where Callable is used to annotate an input parameter, and the Callable return type is a union that contains a type variable.
Bug Fix: Fixed bug in constraint solver relating to replacement of return type of the form T when matching was performed against Type[T].
Enhancement: Added support for __builtins__ module symbol symbol.
Enhancement: Added support for type narrowing conditional expressions of the form a is False, a is True, a is not False and a is not True.