typing(type): add type annotations to add_promotion_rule

nstarman · nstarman · commit d20e0d0d08b1 · 2025-01-07T16:39:15.000-05:00
Signed-off-by: Nathaniel Starkman &lt;nstarman@users.noreply.github.com&gt;
diff --git a/plum/promotion.py b/plum/promotion.py
@@ -135,7 +135,7 @@ def _promotion_rule(type1, type2):
 
 
 @_dispatch
-def add_promotion_rule(type1, type2, type_to):
+def add_promotion_rule(type1: type, type2: type, type_to: type) -> None:
     """Add a promotion rule.
 
     Args:
