From bbf7304946978acd4a620edeccae7610dcf7b563 Mon Sep 17 00:00:00 2001
From: blueloveTH <blueloveth@foxmail.com>
Date: Fri, 1 Mar 2024 16:52:21 +0800
Subject: [PATCH] fix a common bad usage

---
 include/pocketpy/obj.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/pocketpy/obj.h b/include/pocketpy/obj.h
index bf76e63c..6ac99848 100644
--- a/include/pocketpy/obj.h
+++ b/include/pocketpy/obj.h
@@ -171,6 +171,8 @@ template <typename T> struct has_gc_marker<T, std::void_t<decltype(&T::_gc_mark)
 
 template <typename T>
 struct Py_ final: PyObject {
+    static_assert(!std::is_reference_v<T>, "T must not be a reference type. Are you using `PK_OBJ_GET(T&, ...)`?");
+
     T _value;
     void _obj_gc_mark() override {
         if constexpr (has_gc_marker<T>::value) {