Yes, from that explanation it sounds like they are equivalent to Rust’s impl return types.

Note that interfaces in Rust are not types, they do not name types. A value cannot have interface type. What happens when you return an “impl” type is that you return some unspecified type, but that type must implement the specified interface.

You could translate the D example to:

    trait HasGetValue {
        fn get_value(&self) -> i32;
    }
    fn create_voldemort_type(value: i32) -> impl HasGetValue {
        ...
    }

The “create_voldemort_type” function simply returns a value of unspecified type. As far as I can tell, this is equivalent to the D code, except it doesn’t use type inference for the function type.