Define generics from a different function

jedi/evaluate/context/instance.py

@@ -279,8 +279,7 @@ class TreeInstance(AbstractInstanceContext):
                 continue
 
             all_annotations = pep0484.py__annotations__(execution.tree_node)
-            defined = pep0484.define_type_vars(
-                self.class_context,
+            defined = self.class_context.define_generics(
                 pep0484.infer_type_vars_for_execution(execution, all_annotations),
             )
             debug.dbg('Inferred instance context as %s', defined, color='BLUE')

jedi/evaluate/context/iterable.py

@@ -529,6 +529,12 @@ class FakeDict(_DictMixin, _FakeArray):
     def _dict_values(self):
         return ContextSet.from_sets(lazy_context.infer() for lazy_context in self._dct.values())
 
+    def _dict_keys(self):
+        return ContextSet.from_sets(lazy_context.infer() for lazy_context in self.py__iter__())
+
+    def get_mapping_item_contexts(self):
+        return self._dict_keys(), self._dict_values()
+
     def exact_key_items(self):
         return self._dct.items()
 

jedi/evaluate/context/klass.py

@@ -47,7 +47,7 @@ from jedi.evaluate.filters import ParserTreeFilter, TreeNameDefinition, \
     ContextName
 from jedi.evaluate.arguments import unpack_arglist
 from jedi.evaluate.base_context import ContextSet, iterator_to_context_set, \
-    TreeContext
+    TreeContext, NO_CONTEXTS
 
 
 def apply_py__get__(context, base_context):
@@ -274,3 +274,19 @@ class ClassContext(use_metaclass(CachedMetaClass, TreeContext)):
             )
             for index_context in index_context_set
         )
+
+    def define_generics(self, type_var_dict):
+        from jedi.evaluate.context.typing import AnnotatedSubClass
+
+        def remap_type_vars():
+            for type_var in self.list_type_vars():
+                yield type_var_dict.get(type_var.py__name__(), NO_CONTEXTS)
+
+        if type_var_dict:
+            return AnnotatedSubClass(
+                self.evaluator,
+                self.parent_context,
+                self.tree_node,
+                given_types=tuple(remap_type_vars())
+            )
+        return self