#[wasm_bindgen] on Boxed structs

[Jeremy-Code-F]

Summary

I'm attempting to generate JS for a simple struct in Rust -

#[wasm_bindgen]
#[derive(PartialEq, Eq, Clone, Debug)]
pub struct ListNode {
    pub val: i32,
    pub next: Option<Box<ListNode>>,
}

#[wasm_bindgen]
impl ListNode {
    #[wasm_bindgen(constructor)]
    #[inline]
    pub fn new(val: i32) -> Self {
        ListNode { next: None, val }
    }
}

I get two errors in this code, the first on the first line #[wasm_bindgen]

the trait bound `std::boxed::Box<ListNode>: wasm_bindgen::convert::OptionIntoWasmAbi` is not satisfied

the trait `wasm_bindgen::convert::OptionIntoWasmAbi` is not implemented for `std::boxed::Box<ListNode>`

help: the following implementations were found:
        <std::boxed::Box<[T]> as wasm_bindgen::convert::OptionIntoWasmAbi>
        <std::boxed::Box<[f32]> as wasm_bindgen::convert::OptionIntoWasmAbi>
        <std::boxed::Box<[f64]> as wasm_bindgen::convert::OptionIntoWasmAbi>
        <std::boxed::Box<[i16]> as wasm_bindgen::convert::OptionIntoWasmAbi>
      and 10 others
note: required because of the requirements on the impl of `wasm_bindgen::convert::IntoWasmAbi` for `std::option::Option<std::boxed::Box<ListNode>>`rustc(E0277)
lib.rs(41, 1): the trait `wasm_bindgen::convert::OptionIntoWasmAbi` is not implemented for `std::boxed::Box<ListNode>`

and the second on the 5th line pub next: Option<Box<ListNode>>

the trait bound `std::boxed::Box<ListNode>: std::marker::Copy` is not satisfied

the trait `std::marker::Copy` is not implemented for `std::boxed::Box<ListNode>`

note: required because of the requirements on the impl of `std::marker::Copy` for `std::option::Option<std::boxed::Box<ListNode>>`rustc(E0277)
lib.rs(41, 1): required by this bound in `__wbg_get_listnode_next__const::__wbg_get_listnode_next::assert_copy`
lib.rs(45, 15): the trait `std::marker::Copy` is not implemented for `std::boxed::Box<ListNode>`

I tried to impl Copy for Box<ListNode>

but since it's a Box it gives me

the trait `Copy` may not be implemented for this type; the type has a destructor

Copy not allowed on types with destructorsrustc(E0184)
lib.rs(57, 1): Copy not allowed on types with destructors

How should I approach doing this?

Thanks!

Additional Details

Provide any additional details here.

[dariusc93]

Although im not sure what youre attempting to do but the only thing i could think of from the top of my head that may reasonable pub from that field and maybe have a function to obtain the next value and mapping it to a new struct?

#[wasm_bindgen]
#[derive(PartialEq, Eq, Clone, Debug)]
pub struct ListNode {
    pub val: i32,
    next: Option<Box<ListNode>>,
}

#[wasm_bindgen]
impl ListNode {
    #[wasm_bindgen(constructor)]
    #[inline]
    pub fn new(val: i32) -> Self {
        ListNode { next: None, val }
    }

    pub fn next(&self) -> Option<ListNode> {
        self.next.as_ref().map(|n| ListNode {
            val: n.val, next: None
        })
    }
}

Not exactly a preferable option though