One of my annoyances is for something like `impl Foo for T: Deref<U>, U: Foo`. Ie a Foo impl for something that can deref to another type, which impls Foo. Eg a

One of my annoyances is for something like `impl Foo for T: Deref<U>, U: Foo`. Ie a Foo impl for something that can deref to another type, which impls Foo. Eg an Arc, Box, etc. So now that you impl that to support, say, Box - well now if something fails to impl Foo, you'll instead get an error about it not being a Box (iirc, been a while). Ie, my memory is old so forgive me, but the error says something to the effect of your `T` type not being Box<T>`, instead of it simply saying that your T doesn't impl Foo. I ran into this confusing error so many times i just stopped doing blanket deref impls and instead just impl it for `Box<T>` directly. Doing that avoids the weird error entirely. Still, i love Rust. However it, like any lang, is not perfect. Nor should it be.