2.11.0 again

docs/coding/predicates.rst

@@ -69,3 +69,4 @@ Or check whether an instance is of provided type
 ::
     p = x.instanceof(int)
     assert p(2)
+

satella/coding/predicates.py

@@ -56,6 +56,12 @@ class Predicate:
         """
         return make_operation_two_args(_one_of)(self, values)
 
+    def inside(self, value):
+        """
+        Return a predicate checking if x is inside value
+        """
+        return make_operation_two_args(operator.contains)(self, value)
+
     def instanceof(self, instance):
         """
         Return a predicate checking whether this value is an instance of instance

tests/test_coding/test_predicates.py

@@ -53,7 +53,7 @@ class TestPredicates(unittest.TestCase):
         self.assertFalse(p(4))
 
     def test_contains(self):
-        p = 2 in x
+        p = x.inside(2)
         self.assertTrue(p([1, 2]))
         self.assertFalse(p([1, 3]))