gh-112328: Make EnumDict usable on its own and document it (GH-123669)

Co-authored-by: Rafi <rafi.promit@gmail.com>
Co-authored-by: Sviatoslav Sydorenko (Святослав Сидоренко) <wk.cvs.github@sydorenko.org.ua>
Co-authored-by: Ethan Furman <ethan@stoneleaf.us>

1 files changed, 18 insertions, 8 deletions

diff --git a/Doc/library/enum.rst b/Doc/library/enum.rst
index 51292a1..8ca9493 100644
--- a/Doc/library/enum.rst
+++ b/Doc/library/enum.rst
@@ -110,6 +110,10 @@ Module Contents
       ``KEEP`` which allows for more fine-grained control over how invalid values
       are dealt with in an enumeration.
 
+   :class:`EnumDict`
+
+      A subclass of :class:`dict` for use when subclassing :class:`EnumType`.
+
    :class:`auto`
 
       Instances are replaced with an appropriate value for Enum members.
@@ -149,14 +153,10 @@ Module Contents
 
       Return a list of all power-of-two integers contained in a flag.
 
-   :class:`EnumDict`
-
-      A subclass of :class:`dict` for use when subclassing :class:`EnumType`.
-
 
 .. versionadded:: 3.6  ``Flag``, ``IntFlag``, ``auto``
 .. versionadded:: 3.11  ``StrEnum``, ``EnumCheck``, ``ReprEnum``, ``FlagBoundary``, ``property``, ``member``, ``nonmember``, ``global_enum``, ``show_flag_values``
-.. versionadded:: 3.14  ``EnumDict``
+.. versionadded:: 3.13  ``EnumDict``
 
 ---------------
 
@@ -830,13 +830,23 @@ Data Types
 
 .. class:: EnumDict
 
-   *EnumDict* is a subclass of :class:`dict` for use when subclassing :class:`EnumType`.
+   *EnumDict* is a subclass of :class:`dict` that is used as the namespace
+   for defining enum classes (see :ref:`prepare`).
+   It is exposed to allow subclasses of :class:`EnumType` with advanced
+   behavior like having multiple values per member.
+   It should be called with the name of the enum class being created, otherwise
+   private names and internal classes will not be handled correctly.
+
+   Note that only the :class:`~collections.abc.MutableMapping` interface
+   (:meth:`~object.__setitem__` and :meth:`~dict.update`) is overridden.
+   It may be possible to bypass the checks using other :class:`!dict`
+   operations like :meth:`|= <object.__ior__>`.
 
    .. attribute:: EnumDict.member_names
 
-      Return list of member names.
+      A list of member names.
 
-   .. versionadded:: 3.14
+   .. versionadded:: 3.13
 
 ---------------