Support Option<Vec<T>> where T is primitive

[NiwakaDev]

This PR addresses #146 and introduces Option<Vec<T>> where T is primitive.

Here's an example of using Option<Vec<T>>:

//Rust 
#[swift_bridge::bridge]
mod ffi {
    extern "Rust" {
        fn rust_reflect_option_vector_rust_type(arg: Option<Vec<u16>>) -> Option<Vec<u16>>;
    }
}

//Swift 
let vec = RustVec<UInt16>()
vec.push(value: 123)
vec.push(value: 321)
let reflected = rust_reflect_option_vector_rust_type(vec)
XCTAssertEqual(reflected.len(), 2)

XCTAssertEqual(reflected.get(index: 0), 123)
XCTAssertEqual(reflected.get(index: 1), 321)

XCTAssertNil(rust_reflect_option_vector_rust_type(nil))

[chinedufn]

This is really great work.

Left some minor feedback but overall this looks good.

Thanks for diving in and figuring all of this out.

[chinedufn]

The only reason that this works is because vec doesn't get dropped when you call rust_reflect_option_vector_rust_type.
Otherwise this would be a use after free.

You can change this to:

// ...

let reflected = rust_reflect_option_vector_rust_type(vec)
XCTAssertEqual(reflected.len(), 2)

XCTAssertEqual(reflected.get(index: 0), 123)
XCTAssertEqual(reflected.get(index: 1), 321)

// ...

[chinedufn]

Oh and please also update the example in the PR body. I plan to copy and paste it into the release notes.

[NiwakaDev]

I plan to copy and paste it into the release notes.

Do I also need to change rust-code?

[chinedufn]

It's fine I'll rename it to something shorter in the release notes

[chinedufn]

testSwiftCallRustWithOptionVecOfPrimitiveType

[chinedufn]

MINOR:

Can we move this test below extern_rust_fn_option_primitive.

I think that the tests are easier to follow if we start with the simple scenarios are gradually build up to more complex scenarios.

[chinedufn]

Awesome work in this file

[chinedufn]

MINOR:
typo in extern

[chinedufn]

MINOR:
typo in extern

[NiwakaDev]

Addressed your review! Please let me know if there are any omissions or errors.

[chinedufn]

Looks great!