├── .github └── workflows │ └── ci.yml ├── .gitignore ├── Cargo.toml ├── LICENSE-APACHE ├── LICENSE-MIT ├── README.md ├── src ├── lib.rs ├── projection.rs └── stack_pin.rs └── tests ├── projection.rs └── stack_pin.rs /.github/workflows/ci.yml: -------------------------------------------------------------------------------- 1 | name: CI 2 | 3 | permissions: 4 | contents: read 5 | 6 | on: 7 | pull_request: 8 | push: 9 | branches: 10 | - master 11 | schedule: 12 | - cron: "0 1 * * 0" 13 | 14 | env: 15 | CARGO_INCREMENTAL: 0 16 | CARGO_NET_RETRY: 10 17 | CARGO_TERM_COLOR: always 18 | RUST_BACKTRACE: 1 19 | RUSTDOCFLAGS: -D warnings 20 | RUSTFLAGS: -D warnings 21 | RUSTUP_MAX_RETRIES: 10 22 | 23 | defaults: 24 | run: 25 | shell: bash 26 | 27 | jobs: 28 | test: 29 | strategy: 30 | matrix: 31 | rust: 32 | # This is the minimum supported Rust version of this crate. 33 | # When updating this, the reminder to update the minimum supported 34 | # Rust version in README.md. 35 | - 1.33.0 36 | - stable 37 | - beta 38 | - nightly 39 | runs-on: ubuntu-latest 40 | steps: 41 | - uses: actions/checkout@v4 42 | - name: Install Rust 43 | run: rustup update ${{ matrix.rust }} && rustup default ${{ matrix.rust }} 44 | - run: cargo build 45 | - run: cargo test 46 | - run: cargo test --release 47 | 48 | clippy: 49 | runs-on: ubuntu-latest 50 | steps: 51 | - uses: actions/checkout@v4 52 | - name: Install Rust 53 | run: rustup update stable 54 | - run: cargo clippy --all --all-targets 55 | 56 | rustfmt: 57 | runs-on: ubuntu-latest 58 | steps: 59 | - uses: actions/checkout@v4 60 | - name: Install Rust 61 | run: rustup update stable 62 | - run: cargo fmt --all --check 63 | 64 | rustdoc: 65 | runs-on: ubuntu-latest 66 | steps: 67 | - uses: actions/checkout@v4 68 | - name: Install Rust 69 | run: rustup update nightly && rustup default nightly 70 | - run: cargo doc --no-deps 71 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | target/ 2 | **/*.rs.bk 3 | Cargo.lock 4 | -------------------------------------------------------------------------------- /Cargo.toml: -------------------------------------------------------------------------------- 1 | [package] 2 | name = "pin-utils" 3 | edition = "2018" 4 | version = "0.1.0" 5 | authors = ["Josef Brandl "] 6 | license = "MIT OR Apache-2.0" 7 | readme = "README.md" 8 | repository = "https://github.com/rust-lang/pin-utils" 9 | documentation = "https://docs.rs/pin-utils" 10 | description = """ 11 | Utilities for pinning 12 | """ 13 | -------------------------------------------------------------------------------- /LICENSE-APACHE: -------------------------------------------------------------------------------- 1 | Apache License 2 | Version 2.0, January 2004 3 | http://www.apache.org/licenses/ 4 | 5 | TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 6 | 7 | 1. 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IN NO EVENT 21 | SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY 22 | CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 23 | OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR 24 | IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 25 | DEALINGS IN THE SOFTWARE. 26 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # pin-utils 2 | 3 | [![crates-badge]][crates-url] 4 | [![docs-badge]][docs-url] 5 | [![license-badge]][license] 6 | [![rustc-badge]][rustc-url] 7 | 8 | [crates-badge]: https://img.shields.io/crates/v/pin-utils.svg 9 | [crates-url]: https://crates.io/crates/pin-utils 10 | [docs-badge]: https://docs.rs/pin-utils/badge.svg 11 | [docs-url]: https://docs.rs/pin-utils 12 | [license-badge]: https://img.shields.io/crates/l/pin-utils.svg 13 | [license]: #license 14 | [rustc-badge]: https://img.shields.io/badge/rustc-1.33+-lightgray.svg 15 | [rustc-url]: https://blog.rust-lang.org/2019/02/28/Rust-1.33.0.html 16 | 17 | Utilities for pinning 18 | 19 | [Documentation][docs-url] 20 | 21 | **Note:** Since Rust 1.68, all APIs in this crate are now soft-deprecated or deprecated: 22 | 23 | - `pin_utils::pin_mut!` is soft-deprecated in favor of [`pin!` macro in the standard library](https://doc.rust-lang.org/std/pin/macro.pin.html) that stabilized in Rust 1.68. 24 | - `pin_utils::{unsafe_pinned,unsafe_unpinned}` are **deprecated** in favor of safe alternatives: [pin-project](https://crates.io/crates/pin-project), [pin-project-lite](https://crates.io/crates/pin-project-lite) 25 | 26 | ## Usage 27 | 28 | First, add this to your `Cargo.toml`: 29 | 30 | ```toml 31 | [dependencies] 32 | pin-utils = "0.1" 33 | ``` 34 | 35 | Now, you can use it: 36 | 37 | ```rust 38 | use pin_utils::pin_mut; // And more... 39 | ``` 40 | 41 | The current pin-utils requires Rust 1.33 or later. 42 | 43 | # License 44 | 45 | This project is licensed under either of 46 | 47 | * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or 48 | http://www.apache.org/licenses/LICENSE-2.0) 49 | * MIT license ([LICENSE-MIT](LICENSE-MIT) or 50 | http://opensource.org/licenses/MIT) 51 | 52 | at your option. 53 | 54 | ### Contribution 55 | 56 | Unless you explicitly state otherwise, any contribution intentionally submitted 57 | for inclusion in pin-utils by you, as defined in the Apache-2.0 license, shall be 58 | dual licensed as above, without any additional terms or conditions. 59 | -------------------------------------------------------------------------------- /src/lib.rs: -------------------------------------------------------------------------------- 1 | //! Utilities for pinning 2 | //! 3 | //! **Note:** Since Rust 1.68, all APIs in this crate are now soft-deprecated or deprecated: 4 | //! 5 | //! - `pin_utils::pin_mut!` is soft-deprecated in favor of [`pin!` macro in the standard library](https://doc.rust-lang.org/std/pin/macro.pin.html) that stabilized in Rust 1.68. 6 | //! - `pin_utils::{unsafe_pinned,unsafe_unpinned}` are **deprecated** in favor of safe alternatives: [pin-project](https://crates.io/crates/pin-project), [pin-project-lite](https://crates.io/crates/pin-project-lite) 7 | 8 | #![no_std] 9 | #![warn(missing_docs, missing_debug_implementations, rust_2018_idioms)] 10 | 11 | #[macro_use] 12 | mod stack_pin; 13 | #[macro_use] 14 | mod projection; 15 | 16 | // Not public API. 17 | #[doc(hidden)] 18 | pub mod __private { 19 | pub use core::pin::Pin; 20 | } 21 | -------------------------------------------------------------------------------- /src/projection.rs: -------------------------------------------------------------------------------- 1 | /// A pinned projection of a struct field. 2 | /// 3 | /// # Safety 4 | /// 5 | /// To make using this macro safe, three things need to be ensured: 6 | /// - If the struct implements [`Drop`], the [`drop`] method is not allowed to 7 | /// move the value of the field. 8 | /// - If the struct wants to implement [`Unpin`], it has to do so conditionally: 9 | /// The struct can only implement [`Unpin`] if the field's type is [`Unpin`]. 10 | /// - The struct must not be `#[repr(packed)]`. 11 | /// 12 | /// # Example 13 | /// 14 | /// ```rust 15 | /// use pin_utils::unsafe_pinned; 16 | /// use std::marker::Unpin; 17 | /// use std::pin::Pin; 18 | /// 19 | /// struct Foo { 20 | /// field: T, 21 | /// } 22 | /// 23 | /// impl Foo { 24 | /// unsafe_pinned!(field: T); 25 | /// 26 | /// fn baz(mut self: Pin<&mut Self>) { 27 | /// let _: Pin<&mut T> = self.field(); // Pinned reference to the field 28 | /// } 29 | /// } 30 | /// 31 | /// impl Unpin for Foo {} // Conditional Unpin impl 32 | /// ``` 33 | /// 34 | /// Note: borrowing the field multiple times requires using `.as_mut()` to 35 | /// avoid consuming the `Pin`. 36 | /// 37 | /// [`Unpin`]: core::marker::Unpin 38 | /// [`drop`]: Drop::drop 39 | #[deprecated( 40 | since = "0.1.1", 41 | note = "this macro is not safe; use safe pin-project or pin-project-lite crate instead" 42 | )] 43 | #[macro_export] 44 | macro_rules! unsafe_pinned { 45 | ($f:tt: $t:ty) => { 46 | #[allow(unsafe_code)] 47 | fn $f<'__a>( 48 | self: $crate::__private::Pin<&'__a mut Self>, 49 | ) -> $crate::__private::Pin<&'__a mut $t> { 50 | unsafe { $crate::__private::Pin::map_unchecked_mut(self, |x| &mut x.$f) } 51 | } 52 | }; 53 | } 54 | 55 | /// An unpinned projection of a struct field. 56 | /// 57 | /// # Safety 58 | /// 59 | /// This macro is unsafe because it creates a method that returns a normal 60 | /// non-pin reference to the struct field. It is up to the programmer to ensure 61 | /// that the contained value can be considered not pinned in the current 62 | /// context. 63 | /// 64 | /// # Example 65 | /// 66 | /// ```rust 67 | /// use pin_utils::unsafe_unpinned; 68 | /// use std::pin::Pin; 69 | /// 70 | /// struct Bar; 71 | /// struct Foo { 72 | /// field: Bar, 73 | /// } 74 | /// 75 | /// impl Foo { 76 | /// unsafe_unpinned!(field: Bar); 77 | /// 78 | /// fn baz(mut self: Pin<&mut Self>) { 79 | /// let _: &mut Bar = self.field(); // Normal reference to the field 80 | /// } 81 | /// } 82 | /// ``` 83 | /// 84 | /// Note: borrowing the field multiple times requires using `.as_mut()` to 85 | /// avoid consuming the [`Pin`]. 86 | /// 87 | /// [`Pin`]: core::pin::Pin 88 | #[deprecated( 89 | since = "0.1.1", 90 | note = "this macro is not safe; use safe pin-project or pin-project-lite crate instead" 91 | )] 92 | #[macro_export] 93 | macro_rules! unsafe_unpinned { 94 | ($f:tt: $t:ty) => { 95 | #[allow(unsafe_code)] 96 | fn $f<'__a>(self: $crate::__private::Pin<&'__a mut Self>) -> &'__a mut $t { 97 | unsafe { &mut $crate::__private::Pin::get_unchecked_mut(self).$f } 98 | } 99 | }; 100 | } 101 | -------------------------------------------------------------------------------- /src/stack_pin.rs: -------------------------------------------------------------------------------- 1 | /// Pins a value on the stack. 2 | /// 3 | /// Can safely pin values that are not `Unpin` by taking ownership. 4 | /// 5 | /// **Note:** Since Rust 1.68, this macro is soft-deprecated in favor of 6 | /// [`pin!`](core::pin::pin) macro in the standard library. 7 | /// 8 | /// # Example 9 | /// 10 | /// ```rust 11 | /// # use pin_utils::pin_mut; 12 | /// # use core::pin::Pin; 13 | /// # struct Foo {} 14 | /// let foo = Foo { /* ... */ }; 15 | /// pin_mut!(foo); 16 | /// let _: Pin<&mut Foo> = foo; 17 | /// ``` 18 | #[macro_export] 19 | macro_rules! pin_mut { 20 | ($($x:ident),* $(,)?) => { $( 21 | // Move the value to ensure that it is owned 22 | let mut $x = $x; 23 | // Shadow the original binding so that it can't be directly accessed 24 | // ever again. 25 | #[allow(unused_mut)] 26 | let mut $x = unsafe { 27 | $crate::__private::Pin::new_unchecked(&mut $x) 28 | }; 29 | )* } 30 | } 31 | -------------------------------------------------------------------------------- /tests/projection.rs: -------------------------------------------------------------------------------- 1 | #![allow(deprecated)] 2 | 3 | use pin_utils::{pin_mut, unsafe_pinned, unsafe_unpinned}; 4 | use std::pin::Pin; 5 | 6 | struct Foo { 7 | field1: T1, 8 | field2: T2, 9 | } 10 | 11 | impl Foo { 12 | unsafe_pinned!(field1: T1); 13 | unsafe_unpinned!(field2: T2); 14 | } 15 | 16 | impl Unpin for Foo {} // Conditional Unpin impl 17 | 18 | #[test] 19 | fn projection() { 20 | let x = Foo { 21 | field1: 1, 22 | field2: 2, 23 | }; 24 | pin_mut!(x); 25 | 26 | let x1: Pin<&mut i32> = x.as_mut().field1(); 27 | assert_eq!(*x1, 1); 28 | 29 | let x2: &mut i32 = x.as_mut().field2(); 30 | assert_eq!(*x2, 2); 31 | } 32 | -------------------------------------------------------------------------------- /tests/stack_pin.rs: -------------------------------------------------------------------------------- 1 | #![forbid(unsafe_code)] // pin_mut! is completely safe. 2 | 3 | use core::pin::Pin; 4 | use pin_utils::pin_mut; 5 | 6 | #[test] 7 | fn stack_pin() { 8 | struct Foo {} 9 | let x = Foo {}; 10 | pin_mut!(x); 11 | let _: Pin<&mut Foo> = x; 12 | 13 | let y = Foo {}; 14 | let z = Foo {}; 15 | pin_mut!(y, z,); 16 | let _: Pin<&mut Foo> = y; 17 | let _: Pin<&mut Foo> = z; 18 | } 19 | --------------------------------------------------------------------------------