add test for slotted classes

Author: eendebakpt

Lib/test/test_functools.py

@@ -2474,6 +2474,26 @@ def _(arg):
         self.assertTrue(A.t(''))
         self.assertEqual(A.t(0.0), 0.0)
 
+    def test_staticmethod__slotted_class(self):
+        class A:
+            __slots__ = ['a']
+            @functools.singledispatchmethod
+            def t(arg):
+                return arg
+            @t.register(int)
+            @staticmethod
+            def _(arg):
+                return isinstance(arg, int)
+            @t.register(str)
+            @staticmethod
+            def _(arg):
+                return isinstance(arg, str)
+        a = A()
+
+        self.assertTrue(A.t(0))
+        self.assertTrue(A.t(''))
+        self.assertEqual(A.t(0.0), 0.0)
+
     def test_classmethod_register(self):
         class A:
             def __init__(self, arg):