From fb7d426919f8d3f33e82f75982d5b8dcaf171f71 Mon Sep 17 00:00:00 2001
From: Congyu <leonwang998@gmail.com>
Date: Sun, 18 Feb 2024 12:13:45 +0800
Subject: [PATCH] add test to ensure that !Send and !Sync

---
 src/lib.rs | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/lib.rs b/src/lib.rs
index e2c608f..6f40c0f 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -7,6 +7,24 @@ use std::{
 };
 
 /// Owned cell for data.
+///
+/// The data structure is not thread safe.
+/// It is not even safe to move to another thread.
+/// (i.e., !Send).
+/// ```compile_fail,E0433
+/// use std::sync::atomic::AtomicUsize;
+///
+/// fn impl_send<T: Send>(val: T) {}
+/// impl_send(LinkNode::new(AtomicUsize::new(0)));
+/// ```
+///
+/// Nor sync:
+/// ```compile_fail,E0433
+/// use std::sync::atomic::AtomicUsize;
+///
+/// fn impl_sync<T: Sync>(val: T) {}
+/// impl_sync(LinkNode::new(AtomicUsize::new(0)));
+/// ```
 pub struct LinkNode<T>(Pin<Box<Inner<T>>>);
 
 /// Pinned on heap for linking.