with interior mutability and reference counting, you must
ensure that you don’t create cycles; you can’t rely on Rust to catch them.
Creating a reference cycle would be a logic bug in your program that you should
use automated tests, code reviews, and other software development practices to
minimize.
-->
<p>循環参照は簡単にできることではありませんが、不可能というわけでもありません。
<code>Rc&lt;T&gt;</code>値を含む<code>RefCell&lt;T&gt;</code>値があるなど�