Auto-derived Clone for something using RcPointer is unusable

[orium]

Issue created for future reference.

This is a rustc issue in the way Clone is derived.

The problem is that

#[derive(Clone)] 
struct AThing<T, C: RcPointerKind> {
    field: RcPointer<C, T>,
}

expands to

impl<T: Clone, C: Clone + RcPointerKind> Clone for AThing<T, C> { ... }

which requires C to implement Clone. In practice it should only require the type of AThing::field to be implement Clone. See rust-lang/rust#26925 (comment) for details.