How can I copy the fields of another structure?

Question

Is there any crate or functionality that allows me to copy the fields from another structure?

Crate A

struct Product {
    name: String,
    sku: String,
    amount: i32,
}

Crate B

#[derive(copy_fields_from = "a::Product", InputObject)]
struct ProductApi {}

I have to expose several objects from another crate in an API that uses "#[derive(InputObject)]". For that, I have to duplicate all the structures of the other structure. Is it possible to copy the fields of another structure? Perhaps using hypothetical syntax such as #[derive(copy_fields_from ="a::Product")].

Does the [newtype pattern](https://doc.rust-lang.org/1.0.0/style/features/types/newtype.html) not work for you? — orlp, Nov 18 '20 at 21:47
no, because `async_graphql::InputObject ` adds functionality to the structure — BeGo, Nov 18 '20 at 22:38

score 1 · Answer 1 · answered Nov 19 '20 at 02:40

No, there is no way of doing this cleanly.

If you felt you had to do this, you'd need to write a build script that:

Located the source code of the target crate.
Parsed the source code using a crate like syn.
Located the types in question.
Output them again.

How can I copy the fields of another structure?

1 Answers1