bpo-32996: Documentation fix-up. (GH-16646)

miss-islington · eirrgang · web-flow · commit ca012360b103 · 2019-10-10T04:17:05.000-07:00
PR GH-4906 changed the typing.Generic class hierarchy, leaving an outdated comment in the library reference. User-defined Generic ABCs now must get a abc.ABCMeta metaclass from something other than typing.Generic inheritance. (cherry picked from commit d47f0dd) Co-authored-by: M. Eric Irrgang <mei2n@virginia.edu>
diff --git a/Doc/library/typing.rst b/Doc/library/typing.rst
@@ -306,9 +306,10 @@ User defined generic type aliases are also supported. Examples::
    def inproduct(v: Vec[T]) -> T: # Same as Iterable[Tuple[T, T]]
        return sum(x*y for x, y in v)
 
-The metaclass used by :class:`Generic` is a subclass of :class:`abc.ABCMeta`.
-A generic class can be an ABC by including abstract methods or properties,
-and generic classes can also have ABCs as base classes without a metaclass
+.. versionchanged:: 3.7
+    :class:`Generic` no longer has a custom metaclass.
+
+A user-defined generic class can have ABCs as base classes without a metaclass
 conflict. Generic metaclasses are not supported. The outcome of parameterizing
 generics is cached, and most types in the typing module are hashable and
 comparable for equality.
