It seems that boxed slices (
Box<[T]>) are pretty common but boxed arrays (
Box<[T; N]>) are not.
I haven't done an extensive search, but one place I've found this is in the object crate. I don't really understand the code but my impression is that it's kind of using the boxed array like a struct.
Context: I'm working on a guide to contiguous data in Rust. I'm pretty sure boxed arrays are rare enough to not need to mention, but it made me curious what they can be used for!