<p><span class="h-card" translate="no"><a href="https://mastodon.social/@whitequark" class="u-url mention">@<span>whitequark</span></a></span> <span class="h-card" translate="no"><a href="https://mastodon.social/@tef" class="u-url mention">@<span>tef</span></a></span> It feels like completion callbacks and/or ring based systems are essentially similar to things like signal handling or ISRs, in that you ultimately have to move the ownership of some stuff (like buffers, callback text and arguments, descriptors, etc) into the framework that manages the OS or hardware facility directly rather than create and destroy it in the consumers lexical context. The RAII-able thing would be a lease on a buffer basically, which might not free until later.</p>