diff --git a/README.md b/README.md index 143b4674c3..1a841a4c99 100644 --- a/README.md +++ b/README.md @@ -107,6 +107,29 @@ memory model, and *any future memory model*. We ensure this by: [Miri]: https://github.com/rust-lang/miri [Kani]: https://github.com/model-checking/kani +## Relationship to Project Safe Transmute + +[Project Safe Transmute] is an official initiative of the Rust Project to +develop language-level support for safer transmutation. The Project consults +with crates like zerocopy to identify aspects of safer transmutation that +would benefit from compiler support, and has developed an [experimental, +compiler-supported analysis][mcp-transmutability] which determines whether, +for a given type, any value of that type may be soundly transmuted into +another type. Once this functionality is sufficiently mature, zerocopy +intends to replace its internal transmutability analysis (implemented by our +custom derives) with the compiler-supported one. This change will likely be +an implementation detail that is invisible to zerocopy's users. + +Project Safe Transmute will not replace the need for most of zerocopy's +higher-level abstractions. The experimental compiler analysis is a tool for +checking the soundness of `unsafe` code, not a tool to avoid writing +`unsafe` code altogether. For the foreseeable future, crates like zerocopy +will still be required in order to provide higher-level abstractions on top +of the building block provided by Project Safe Transmute. + +[Project Safe Transmute]: https://rust-lang.github.io/rfcs/2835-project-safe-transmute.html +[mcp-transmutability]: https://github.com/rust-lang/compiler-team/issues/411 + ## Disclaimer Disclaimer: Zerocopy is not an officially supported Google product. diff --git a/src/lib.rs b/src/lib.rs index c7c0899979..c98d65ad21 100644 --- a/src/lib.rs +++ b/src/lib.rs @@ -105,6 +105,29 @@ //! //! [Miri]: https://github.com/rust-lang/miri //! [Kani]: https://github.com/model-checking/kani +//! +//! # Relationship to Project Safe Transmute +//! +//! [Project Safe Transmute] is an official initiative of the Rust Project to +//! develop language-level support for safer transmutation. The Project consults +//! with crates like zerocopy to identify aspects of safer transmutation that +//! would benefit from compiler support, and has developed an [experimental, +//! compiler-supported analysis][mcp-transmutability] which determines whether, +//! for a given type, any value of that type may be soundly transmuted into +//! another type. Once this functionality is sufficiently mature, zerocopy +//! intends to replace its internal transmutability analysis (implemented by our +//! custom derives) with the compiler-supported one. This change will likely be +//! an implementation detail that is invisible to zerocopy's users. +//! +//! Project Safe Transmute will not replace the need for most of zerocopy's +//! higher-level abstractions. The experimental compiler analysis is a tool for +//! checking the soundness of `unsafe` code, not a tool to avoid writing +//! `unsafe` code altogether. For the foreseeable future, crates like zerocopy +//! will still be required in order to provide higher-level abstractions on top +//! of the building block provided by Project Safe Transmute. +//! +//! [Project Safe Transmute]: https://rust-lang.github.io/rfcs/2835-project-safe-transmute.html +//! [mcp-transmutability]: https://github.com/rust-lang/compiler-team/issues/411 // Sometimes we want to use lints which were added after our MSRV. // `unknown_lints` is `warn` by default and we deny warnings in CI, so without