From 96da64bc5eb05e55332fd7bb381171d4d69971bb Mon Sep 17 00:00:00 2001
From: Cheuk Ting Ho <cheukting.ho@gmail.com>
Date: Wed, 9 Oct 2024 18:30:37 +0100
Subject: [PATCH] seal PyAddToModule (#4606)

* seal PyAddToModule

* adding change log

* fix changelog name
---
 newsfragments/4606.changed.md |  1 +
 src/impl_/pymodule.rs         |  2 +-
 src/sealed.rs                 | 10 ++++++++++
 3 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 newsfragments/4606.changed.md

diff --git a/newsfragments/4606.changed.md b/newsfragments/4606.changed.md
new file mode 100644
index 00000000000..173252992c1
--- /dev/null
+++ b/newsfragments/4606.changed.md
@@ -0,0 +1 @@
+Seal `PyAddToModule` trait.
diff --git a/src/impl_/pymodule.rs b/src/impl_/pymodule.rs
index 97eb2103dfe..da17fe4bbdc 100644
--- a/src/impl_/pymodule.rs
+++ b/src/impl_/pymodule.rs
@@ -144,7 +144,7 @@ impl ModuleDef {
 /// Trait to add an element (class, function...) to a module.
 ///
 /// Currently only implemented for classes.
-pub trait PyAddToModule {
+pub trait PyAddToModule: crate::sealed::Sealed {
     fn add_to_module(&'static self, module: &Bound<'_, PyModule>) -> PyResult<()>;
 }
 
diff --git a/src/sealed.rs b/src/sealed.rs
index 20f31f82e01..fef7a02aca7 100644
--- a/src/sealed.rs
+++ b/src/sealed.rs
@@ -5,6 +5,11 @@ use crate::types::{
 };
 use crate::{ffi, Bound, PyAny, PyResult};
 
+use crate::impl_::{
+    pymethods::PyMethodDef,
+    pymodule::{AddClassToModule, AddTypeToModule, ModuleDef},
+};
+
 pub trait Sealed {}
 
 // for FfiPtrExt
@@ -36,3 +41,8 @@ impl Sealed for Bound<'_, PyType> {}
 impl Sealed for Bound<'_, PyWeakref> {}
 impl Sealed for Bound<'_, PyWeakrefProxy> {}
 impl Sealed for Bound<'_, PyWeakrefReference> {}
+
+impl<T> Sealed for AddTypeToModule<T> {}
+impl<T> Sealed for AddClassToModule<T> {}
+impl Sealed for PyMethodDef {}
+impl Sealed for ModuleDef {}