... and through type casts

Cython/Compiler/ExprNodes.py

@@ -3826,6 +3826,9 @@ class TypecastNode(NewTempExprNode):
     def check_const(self):
         self.operand.check_const()
 
+    def calculate_constant_result(self):
+        self.constant_result = self.operand.constant_result
+    
     def calculate_result_code(self):
         opnd = self.operand
         return self.type.cast_code(opnd.result())