pin-project

An attribute that creates a projection struct covering all the fields.

Documentation

Usage

Add this to your Cargo.toml:

[dependencies]
pin-project = "0.3"

The current version of pin-project requires Rust 1.33 or later.

Examples

unsafe_project attribute creates a projection struct covering all the fields.

use pin_project::unsafe_project;
use std::pin::Pin;

#[unsafe_project(Unpin)] // `(Unpin)` is optional (create the appropriate conditional Unpin implementation)
struct Foo<T, U> {
    #[pin]
    future: T,
    field: U,
}

impl<T, U> Foo<T, U> {
    fn baz(mut self: Pin<&mut Self>) {
        let this = self.project();
        let _: Pin<&mut T> = this.future; // Pinned reference to the field
        let _: &mut U = this.field; // Normal reference to the field
    }
}

// Automatically create the appropriate conditional Unpin implementation (optional).
// impl<T, U> Unpin for Foo<T, U> where T: Unpin {}

Code like this will be generated

License

Licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.