Dyn Trait in struct with inner Rc

help
1

Why can't I write the following code?

trait MyTrait {
    fn my_fun(&self);
}

struct MyStruct<T:MyTrait> {
    a: Rc<T>
}

fn main() {
    let x: MyStruct<dyn MyTrait> = (...);
}

It seems to me that, at least conceptually, it should be correct.

2

Because, as the compiler error tells, T: MyTrait implicitly means T: MyTrait + Sized, and dyn MyTrait is not Sized.

3

Thanks.

4

This topic was automatically closed 90 days after the last reply. We invite you to open a new topic if you have further questions or comments.