bpo-32717: Document PEP 560 (GH-6726)
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 1e93ef4..b4a0dbf 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -1857,11 +1857,27 @@
When a class definition is executed, the following steps occur:
+* MRO entries are resolved
* the appropriate metaclass is determined
* the class namespace is prepared
* the class body is executed
* the class object is created
+
+Resolving MRO entries
+^^^^^^^^^^^^^^^^^^^^^
+
+If a base that appears in class definition is not an instance of :class:`type`,
+then an ``__mro_entries__`` method is searched on it. If found, it is called
+with the original bases tuple. This method must return a tuple of classes that
+will be used instead of this base. The tuple may be empty, in such case
+the original base is ignored.
+
+.. seealso::
+
+ :pep:`560` - Core support for typing module and generic types
+
+
Determining the appropriate metaclass
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. index::
@@ -2061,6 +2077,27 @@
module) to the language.
+Emulating generic types
+-----------------------
+
+One can implement the generic class syntax as specified by :pep:`484`
+(for example ``List[int]``) by defining a special method
+
+.. classmethod:: object.__class_getitem__(cls, key)
+
+ Return an object representing the specialization of a generic class
+ by type arguments found in *key*.
+
+This method is looked up on the class object itself, and when defined in
+the class body, this method is implicitly a class method. Note, this
+mechanism is primarily reserved for use with static type hints, other usage
+is discouraged.
+
+.. seealso::
+
+ :pep:`560` - Core support for typing module and generic types
+
+
.. _callable-types:
Emulating callable objects