isinstance

youknowone · youknowone · commit f26054ab4e11 · 2025-06-29T14:38:48.000+09:00
diff --git a/vm/src/builtins/union.rs b/vm/src/builtins/union.rs
@@ -41,7 +41,8 @@ impl PyUnion {
     }
 
     /// Direct access to args field, matching CPython's _Py_union_args
-    pub(crate) fn get_args(&self) -> &PyTupleRef {
+    #[inline]
+    pub fn args(&self) -> &PyTupleRef {
         &self.args
     }
 
diff --git a/vm/src/protocol/object.rs b/vm/src/protocol/object.rs
@@ -513,7 +513,7 @@ impl PyObject {
             let union = cls
                 .downcast_ref::<crate::builtins::PyUnion>()
                 .expect("union is already checked");
-            union.get_args().as_object()
+            union.args().as_object()
         } else {
             cls
         };
@@ -602,16 +602,14 @@ impl PyObject {
 
         // Check for Union type (e.g., int | str) - CPython checks this before tuple
         if cls.class().is(vm.ctx.types.union_type) {
-            if let Ok(args) = cls.get_attr(identifier!(vm, __args__), vm) {
-                if let Ok(tuple) = args.try_to_ref::<PyTuple>(vm) {
-                    for typ in tuple {
-                        if vm
-                            .with_recursion("in __instancecheck__", || self.is_instance(typ, vm))?
-                        {
-                            return Ok(true);
-                        }
-                    }
-                    return Ok(false);
+            // Match CPython's _Py_union_args which directly accesses the args field
+            let union = cls
+                .try_to_ref::<crate::builtins::PyUnion>(vm)
+                .expect("checked by is");
+            let tuple = union.args();
+            for typ in tuple.iter() {
+                if vm.with_recursion("in __instancecheck__", || self.is_instance(typ, vm))? {
+                    return Ok(true);
                 }
             }
         }

Original file line number	Diff line number	Diff line change
`@@ -41,7 +41,8 @@ impl PyUnion {`
`41`	`41`	`}`
`42`	`42`
`43`	`43`	`/// Direct access to args field, matching CPython's _Py_union_args`
`44`		`- pub(crate) fn get_args(&self) -> &PyTupleRef {`
	`44`	`+ #[inline]`
	`45`	`+ pub fn args(&self) -> &PyTupleRef {`
`45`	`46`	`&self.args`
`46`	`47`	`}`
`47`	`48`