return arg

def _type_check(arg, msg, is_argument=True, module=None, *, is_class=False):

def _type_check(arg, msg, is_argument=True, module=None, *, allow_special_forms=False):

"""Check that the argument is a type, and return it (internal helper).

As a special case, accept None and return type(None) instead. Also wrap strings

We append the repr() of the actual value (truncated to 100 chars).

"""

invalid_generic_forms = (Generic, Protocol)

if not is_class:

if not allow_special_forms:

invalid_generic_forms += (ClassVar,)

if is_argument:

invalid_generic_forms += (Final,)

eval(self.__forward_code__, globalns, localns),

"Forward references must evaluate to types.",

is_argument=self.__forward_is_argument__,

is_class=self.__forward_is_class__,

allow_special_forms=self.__forward_is_class__,

)

self.__forward_value__ = _eval_type(

type_, globalns, localns, recursive_guard | {self.__forward_arg__}

"with at least two arguments (a type and an "

"annotation).")

msg = "Annotated[t, ...]: t must be a type."

origin = _type_check(params[0], msg)

origin = _type_check(params[0], msg, allow_special_forms=True)

metadata = tuple(params[1:])

return _AnnotatedAlias(origin, metadata)