Expose dict_contains() and PyDict_Contains() with is about 10% faster
than PySequence_Contains() and more clearly applicable to dicts.
Apply the new function in setobject.c where __contains__ checking is
ubiquitous.
diff --git a/Misc/NEWS b/Misc/NEWS
index f7b1e96..a3f3a18 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -231,6 +231,10 @@
C API
-----
+- Added a new function, PyDict_Contains(d, k) which is like
+ PySequence_Contains() but is specific to dictionaries and executes
+ about 10% faster.
+
- Added three new macros: Py_RETURN_NONE, Py_RETURN_TRUE, and Py_RETURN_FALSE.
Each return the singleton they mention after Py_INCREF()ing them.