gh-141004: Document `PyType_Unwatch` (GH-141414)

diff --git a/Doc/c-api/type.rst b/Doc/c-api/type.rst
index 479ede70b01f5d7ee835c11e62a3ee04c28035ec..29ffeb7c483dcec5749bafd5dea30c5abbf04b9a 100644 (file)
--- a/Doc/c-api/type.rst
+++ b/Doc/c-api/type.rst
@@ -116,6 +116,20 @@ Type Objects
    .. versionadded:: 3.12
 
 
+.. c:function:: int PyType_Unwatch(int watcher_id, PyObject *type)
+
+   Mark *type* as not watched. This undoes a previous call to
+   :c:func:`PyType_Watch`. *type* must not be ``NULL``.
+
+   An extension should never call this function with a *watcher_id* that was
+   not returned to it by a previous call to :c:func:`PyType_AddWatcher`.
+
+   On success, this function returns ``0``. On failure, this function returns
+   ``-1`` with an exception set.
+
+   .. versionadded:: 3.12
+
+
 .. c:type:: int (*PyType_WatchCallback)(PyObject *type)
 
    Type of a type-watcher callback function.