languages/cpython
languages/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython synced 2024-09-18 20:51:39 +00:00
Code Issues Packages Projects Releases Wiki Activity

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

Browse source 
PR #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outdated comment in the library reference.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.
This commit is contained in:
M. Eric Irrgang 2019-10-10 14:11:33 +03:00 committed by Ivan Levkivskyi
parent a05fcd3c7a
commit d47f0dd2e8
1 changed files with 4 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

7
Doc/library/typing.rst
View file

@ -307,9 +307,10 @@ 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.