State-Machine on rustbiteshttps://www.rustbites.com/tags/state-machine/Recent content in State-Machine on rustbitesHugoenFri, 24 Apr 2026 10:36:32 +020099. std::mem::replace — Swap a Value and Keep the Old Onehttps://www.rustbites.com/posts/bite-099/Thu, 23 Apr 2026 17:00:00 +0100https://www.rustbites.com/posts/bite-099/<p><code>mem::take</code> is great until your type doesn&rsquo;t have a sensible <code>Default</code>. That&rsquo;s where <code>mem::replace</code> steps in — you pick what gets left behind, and you still get the old value out of a <code>&amp;mut</code>.</p>