Fix docs

Author: 1st1

Doc/library/exceptions.rst

@@ -367,17 +367,21 @@ The following exceptions are the exceptions that are usually raised.
    raised, and the value returned by the function is used as the
    :attr:`value` parameter to the constructor of the exception.
 
-   If a generator function defined in the presence of a ``from __future__
-   import generator_stop`` directive raises :exc:`StopIteration`, it will be
-   converted into a :exc:`RuntimeError` (retaining the :exc:`StopIteration`
-   as the new exception's cause).
+   If a generator code directly or indirectly raises :exc:`StopIteration`,
+   it is converted into a :exc:`RuntimeError` (retaining the
+   :exc:`StopIteration` as the new exception's cause).
 
    .. versionchanged:: 3.3
       Added ``value`` attribute and the ability for generator functions to
       use it to return a value.
 
    .. versionchanged:: 3.5
-      Introduced the RuntimeError transformation.
+      Introduced the RuntimeError transformation via
+      ``from __future__ import generator_stop``, see :pep:`479`.
+
+   .. versionchanged:: 3.7
+      Enable :pep:`479` for all code by default: a :exc:`StopIteration`
+      error raised in a generator is transformed into a :exc:`RuntimeError`.
 
 .. exception:: StopAsyncIteration
 

Doc/whatsnew/3.7.rst

@@ -935,6 +935,12 @@ that may require changes to your code.
 Changes in Python behavior
 --------------------------
 
+* :pep:`479` is enabled for all code in Python 3.7, meaning that
+  :exc:`StopIteration` exceptions raised directly or indirectly in
+  coroutines and generators are transformed into :exc:`RuntimeError`
+  exceptions.
+  (Contributed by Yury Selivanov in :issue:`32670`.)
+
 * Due to an oversight, earlier Python versions erroneously accepted the
   following syntax::