Are Vec<Struct> return types supported?

[ryankaplan]

Hi again :)

I'm running into an issue and wonder if I'm missing something or if this is by design. I have an array of transparent structs that I'd like to return to Swift. I'd be fine with returning a RustVec, but eventually I want a Swift array of FfiThings structs.

Right now my setup looks like this...

// Thing is a Rust struct that I also expose to wasm, so I'd prefer
// not to move it into `mod ffi`.
impl From<Thing> for ffi::FfiThing {
  ...
}

fn clone_and_into(layers: Vec<Layer>) -> Vec<ffi::FfiLayer> {
    layers.into_iter().map(|l| l.into()).collect()
}

#[swift_bridge::bridge]
mod ffi {
    #[swift_bridge(swift_repr = "struct")]
    struct FfiThing {
       ... simple properties ...
    }

    extern "Rust" {
        // `clone_and_into` is necessary because without it,
        // swift-bridge says that Vec isn't clone-able.
        #[swift_bridge(return_with = clone_and_into)]
        fn get_things() -> Vec<FfiThing>;
    }
}

While the above works fine from a Rust perspective... when I compile Swift the return type is RustVec which doesn't compile because FfiThing isn't vectorizeable. This makes sense to me, since RustVecs are shallow views into Rust, and I want to copy FfiThing over to Swift.

Do you have a recommended path here? Is there a way, for example, to tell the swift-bridge that I want an Array in Swift and not a RustVec? The array and structs in question will be read frequently from Swift, so I really do just want to copy all the data over to Swift rather than repeatedly call into Rust.