Baby Steps

DRANK

After reading boat’s excellent post on asynchronous destructors, I thought it might be a good idea to write some about async fn in traits. Support for async fn in traits is probably the single most common feature request that I hear about. It’s also one of the more complex topics. So I thought it’d be nice to do a blog post kind of giving the “lay of the land” on that feature – what makes it complicated? What questions remain open?I’m not making any concrete proposals in this post, just laying out the problems. But do not lose hope! In a future post, I’ll lay out a specific roadmap for how I think we can make incremental progress towards supporting async fn in traits in a useful way. And, in the meantime, you can use the async-trait crate (but I get ahead of myself…).The goalIn some sense, the goal is simple. We would like to enable you to write traits that include async fn. For example, imagine we have some Database trait that lets you do various operations against a databas…