Rust 1.69.0

Language

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- Deriving built-in traits on packed structs works with Copy fields.

- Stabilize the cmpxchg16b target feature on x86 and x86_64.

- Improve analysis of trait bounds for associated types.

- Allow associated types to be used as union fields.

- Allow Self: Autotrait bounds on dyn-safe trait methods.

- Treat str as containing [u8] for auto trait purposes.

Compiler

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- Upgrade *-pc-windows-gnu on CI to mingw-w64 v10 and GCC 12.2.

- Rework min_choice algorithm of member constraints.

- Support true and false as boolean flags in compiler arguments.

- Default repr(C) enums to c_int size.

Libraries

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- Implement the unstable DispatchFromDyn for cell types, allowing downstream experimentation with custom method receivers.

- Document that fmt::Arguments::as_str() may return Some(_) in more cases after optimization, subject to change.

- Implement AsFd and AsRawFd for Rc.

Stabilized APIs

---------------

- CStr::from_bytes_until_nul

- core::ffi::FromBytesUntilNulError

These APIs are now stable in const contexts:

- SocketAddr::new

- SocketAddr::ip

- SocketAddr::port

- SocketAddr::is_ipv4

- SocketAddr::is_ipv6

- SocketAddrV4::new

- SocketAddrV4::ip

- SocketAddrV4::port

- SocketAddrV6::new

- SocketAddrV6::ip

- SocketAddrV6::port

- SocketAddrV6::flowinfo

- SocketAddrV6::scope_id

Cargo

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- Cargo now suggests cargo fix or cargo clippy --fix when compilation warnings are auto-fixable.

- Cargo now suggests cargo add if you try to install a library crate.

- Cargo now sets the CARGO_BIN_NAME environment variable also for binary examples.

Rustdoc

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- Vertically compact trait bound formatting.

- Only include stable lints in rustdoc::all group.

- Compute maximum Levenshtein distance based on the query.

- Remove inconsistently-present sidebar tooltips.

- Search by macro when query ends with !.

Compatibility Notes

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- The rust-analysis component from rustup now only contains a warning placeholder. This was primarily intended for RLS, and the corresponding -Zsave-analysis flag has been removed from the compiler as well.

- Unaligned references to packed fields are now a hard error. This has been a warning since 1.53, and denied by default with a future-compatibility warning since 1.62.

- Update the minimum external LLVM to 14.

- Cargo now emits errors on invalid characters in a registry token.

- When default-features is set to false of a workspace dependency, and an inherited dependency of a member has default-features = true, Cargo will enable default features of that dependency.

- Cargo denies CARGO_HOME in the [env] configuration table. Cargo itself doesn't pick up this value, but recursive calls to cargo would, which was not intended.

- Debuginfo for build dependencies is now off if not explicitly set. This is expected to improve the overall build time.

- The Rust distribution no longer always includes rustdoc

If tools = [...] is set in bootstrap.toml, we will respect a missing rustdoc in that list. By

default rustdoc remains included. To retain the prior behavior explicitly add "rustdoc" to the

list.

Internal Changes

----------------

These changes do not affect any public interfaces of Rust, but they represent

significant improvements to the performance or internals of rustc and related

tools.

- Move format_args!() into AST (and expand it during AST lowering)