This post examines a particular, seemingly simple problem: given ownership of a Rc<Vec<u32>>, can we write a function that returns an impl Iterator<Item = u32>? It turns out that this is a bit harder than it might at first appear – and, as we’ll see, for good reason. I’ll dig into what’s going on, how you can fix it, and how we might extend the language in the future to try and get past this challenge.

This is the second in a series of posts about Rust compiler errors. Each one will talk about a particular error that I got recently and try to explain (a) why I am getting it and (b) how I fixed it. The purpose of this series of posts is partly to explain Rust, but partly just to gain data for myself. I may also write posts about errors I’m not getting – basically places where I anticipated an error, and used a pattern to avoid it. I hope that after writing enough of these posts, I or others will be able to synthesize some of these facts to make intermediate Rust material, or perhaps to improve the language itself.

I’ve decided to do a little series of posts about Rust compiler errors. Each one will talk about a particular error that I got recently and try to explain (a) why I am getting it and (b) how I fixed it. The purpose of this series of posts is partly to explain Rust, but partly just to gain data for myself. I may also write posts about errors I’m not getting – basically places where I anticipated an error, and used a pattern to avoid it. I hope that after writing enough of these posts, I or others will be able to synthesize some of these facts to make intermediate Rust material, or perhaps to improve the language itself.