traverseda
/
cpython
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

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

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outdated comment in the library reference.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 d47f0dd2e8)

Co-authored-by: M. Eric Irrgang <mei2n@virginia.edu>
This commit is contained in:
Miss Islington (bot) 2019-10-10 04:19:03 -07:00 committed by GitHub
parent 6b6935e563
commit baf8a9b03a
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
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.