Add RustVec.intoArray()

[amsam0]

Hi,

I think it would be quite useful if RustVec had a builtin intoArray method. For example, I had issues using a RustVec in SwiftUI's List (I needed to use the List constructor that takes a children key path).

I was able to fix my issues with this simple extension:

extension RustVec {
    func intoArray() -> [T] {
        var array: [T] = []
        for _ in 0..<self.len() {
            array.append(self.pop()!)
        }
        return array.reversed()
    }
}

It should probably return nil if the RustVec isn't owned.

[chinedufn]

Good idea.

It should probably return nil if the RustVec isn't owned.

It isn't possible to borrow a RustVec today.

In the future when we supported borrowing we would have RustVecRef and RustVecRefMut. Similar to

swift-bridge/book/src/bridge-module/opaque-types/README.md

Lines 52 to 133 in af962ca

	## Owned, Ref and RefMut
	When you define a type in an `extern "Rust"` block, three corresponding Swift classes get generated.
	```swift
	// Equivalent to `SomeType` in Rust
	class SomeType: SomeTypeRefMut {
	// ...
	}
	// Equivalent to `&mut SomeType` in Rust
	class SomeTypeRefMut: SomeTypeRef {
	// ...
	}
	// Equivalent to `&SomeType` in Rust
	class SomeTypeRef {
	// ...
	}
	```
	Here's an example of how `&Type` and `&mut Type` are enforced:
	```rust
	// Rust
	extern "Rust" {
	type SomeType;
	#[swift_bridge(init)]
	fn new() -> SomeType;
	// Callable by SomeType, SomeTypeRef and SomeTypeRefMut.
	fn (&self) everyone();
	// Callable by SomeType, and SomeTypeRefMut.
	fn (&mut self) only_owned_and_ref_mut();
	// Only callable by SomeType.
	fn (self) only_owned();
	}
	extern "Rust" {
	fn make_ref() -> &'static SomeType;
	fn make_ref_mut() -> &'static mut SomeType;
	}
	```
	```swift
	// Swift
	func methods() {
	let someType: SomeType = SomeType()
	let someTypeRef: SomeTypeRef = make_ref()
	let someTypeRefMut: SomeTypeRefMut = make_ref_mut()
	someType.everyone()
	someType.only_owned_and_ref_mut()
	someType.only_owned()
	someTypeRefMut.everyone()
	someTypeRefMut.only_owned_and_ref_mut()
	someTypeRef.everyone()
	}
	func functions() {
	let someType: SomeType = SomeType()
	let someTypeRef: SomeTypeRef = make_ref()
	let someTypeRefMut: SomeTypeRefMut = make_ref_mut()
	takeReference(someType)
	takeReference(someTypeRef)
	takeReference(someTypeRefMut)
	}
	// Can be called with SomeType, SomeTypeRef and SomeTypeRefMut
	func useSomeType(someType: SomeTypeRef) {
	// ...
	}
	```

RustVecRef and RustVecRefMut wouldn't have the intoArray method so it wouldn't be possible to call it on a borrowed Rust vec.

---

If you're interested I'd be happy to merge a PR that adds this intoArray implementation.

Would just leave a TODO to enforce ownership (as in intoArray invalidates the RustVec) after #155 lands