1.68.0 #

• Released on: 9 March, 2023
• Branched from master on: 20 January, 2023

Language #

• Stabilize default_alloc_error_handler This allows usage of alloc on stable without requiring the definition of a handler for allocation failure. Defining custom handlers is still unstable.
• Stabilize efiapi calling convention.
• Remove implicit promotion for types with drop glue

Compiler #

• Change bindings_with_variant_name to deny-by-default
• Allow .. to be parsed as let initializer
• Add armv7-sony-vita-newlibeabihf as a tier 3 target
• Always check alignment during compile-time const evaluation
• Disable “split dwarf inlining” by default.
• Add vendor to Fuchsia’s target triple
• Enable sanitizers for s390x-linux

Libraries #

• Loosen the bound on the Debug implementation of Weak.
• Make std::task::Context !Send and !Sync
• PhantomData layout guarantees
• Don’t derive Debug for OnceWith & RepeatWith
• Implement DerefMut for PathBuf
• Add O(1) Vec -> VecDeque conversion guarantee
• Leak amplification for peek_mut() to ensure BinaryHeap’s invariant is always met

Stabilized APIs #

• {core,std}::pin::pin!
• impl From<bool> for {f32,f64}
• std::path::MAIN_SEPARATOR_STR
• impl DerefMut for PathBuf

These APIs are now stable in const contexts:

• VecDeque::new

Cargo #

• Stabilize sparse registry support for crates.io
• cargo build --verbose tells you more about why it recompiles.
• Show progress of crates.io index update even net.git-fetch-with-cli option enabled

Misc #

Compatibility Notes #

• Only support Android NDK 25 or newer
• Add SEMICOLON_IN_EXPRESSIONS_FROM_MACROS to future-incompat report
• Only specify --target by default for -Zgcc-ld=lld on wasm
• Bump IMPLIED_BOUNDS_ENTAILMENT to Deny + ReportNow
• std::task::Context no longer implements Send and Sync

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.

• Encode spans relative to the enclosing item
• Don’t normalize in AstConv
• Find the right lower bound region in the scenario of partial order relations
• Fix impl block in const expr
• Check ADT fields for copy implementations considering regions
• rustdoc: simplify JS search routine by not messing with lev distance
• Enable ThinLTO for rustc on x86_64-pc-windows-msvc
• Enable ThinLTO for rustc on x86_64-apple-darwin