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swift-bridge facilitates Rust and Swift interop.

Book

You can find information about using Rust and Swift together in The swift-bridge book.

Quick Peek

Share types and functions between Swift and Rust.

```rust // Rust

// You write the type signatures of your FFI boundary in Rust, // which swift-bridge then uses to generate the FFI layer.

[swift_bridge::bridge]

mod ffi { // Create structs that both Swift and Rust can use. #[swiftbridge(swiftrepr = "struct")] struct Comparison { summary: Option, }

// Export Rust types and functions for Swift to use.
extern "Rust" {
    type ARustStack;

    #[swift_bridge(init)]
    fn new() -> ARustStack;

    fn push(&mut self, val: String);
    fn pop(&mut self) -> Option<String>;
}

// Import Swift types and functions for Rust to use.
extern "Swift" {
    type ASwiftGraph;

    fn compare_graphs(g1: &ASwiftGraph, g2: &ASwiftGraph) -> Comparison;
}

}

struct ARustStack { stack: Vec } impl ARustStack { // ... } ```

```swift // Swift

let stack = ARustStack() stack.push("Hello, hello.") let hello = stack.pop()!

class ASwiftGraph { // ... }

func compare_graphs(g1: &ASwiftGraph, g2: &ASwiftGraph) -> Comparison { // ... return Comparison(summary: "Things went well.") } ```

Installation

```toml

In your Cargo.toml

[build-dependencies] swift-bridge-build = "0.1"

[dependencies] swift-bridge = "0.1" ```

Built-In Types

In addition to allowing you to share your own custom types between Rust and Swift, swift_bridge comes with support for a number of Rust and Swift standard library types.

| name in Rust | name in Swift | notes | | --- | --- | --- | | u8, i8, u16, i16... etc | UInt8, Int8, UInt16, Int16 ... etc | | | bool | Bool | | | String, &String, &mut String | RustString, RustStringRef, RustStringRefMut | | | &str | RustStr | | | Vec | RustVec\ | | | SwiftArray\ | Array\ | Not yet implemented | | &[T] | UnsafeBufferPointer\ | | | &mut [T] | UnsafeMutableBufferPointer\ | Not yet implemented | | SwiftString | String | | | Box | | Not yet implemented | | [T; N] | | Not yet implemented | | *const T | UnsafePointer\ | | | *mut T | UnsafeMutablePointer\ | | | Option\ | Optional\ | Currently only supports function return types
Other places such as function arguments are not yet implemented but will come.
| | Result\ | | Not yet implemented | | Have a Rust standard library type in mind?
Open an issue! | | | | | Have a Swift standard library type in mind?
Open an issue! | |

To Test

To run the test suite.

```sh

Clone the repository

git clone git@github.com:chinedufn/swift-bridge.git cd swift-bridge

Run tests

cargo test --all && ./test-integration.sh ```

Early Stages

Bridging Rust and Swift is fairly unexplored territory, so it will take some experimentation in order to figure out the right API and code generation.

In these early days I'm looking for feedback from bleeding-edge users in order to continue to improve the API and the generated code.

I can especially use feedback from people with Swift experience, since I don't have much.

The 0.1.x versions will not follow semver.

We'll maintain semver from 0.2 and onwards.

See Also