A brief summary of the interesting-to-me bits of each Rust release. Shall be updated over time, probably.

Longer notes obvious at https://github.com/rust-lang/rust/releases

1.80

• LazyCell and LazyLock - delays initialization untill first accessed
• Unexpected values in #[cfg(...)] emit warnings
• Better exhaustive checking of ranges in match statements

1.79

• Inline const expressions like let foo = [const { None }; 100];
• Temporary values have lifetime extended in if and match statements

1.78

• Diagnostic attributes for improving custom error messages
• Asserts for checks in unsafe methods enabled in debug mode

1.77

• C-string literals, e.gc"abc" is nul-byte terminated string.
• Recursion in async fn
• Enables stripping of debug info in release mode by default

1.76

• Added any::type_name_of_val method to show string version of type name

1.75

• async fn and -> impl Trait in traits described in more detail in separate post
• Better code layout to reduce application size

1.74

• Lint configuration in Cargo manifest
• Authentication improvements for private Cargo registries

1.73

• Cleaner panic messages
• Tidier thread local init method

1.72

• Some clippy lints added as warnings
• Better error reports on cfg-disabled items

1.71

• Debug viz attributes to improve GDB output etc

1.70

• Spare registry on by default
• IsTerminal, OnceCell and OnceLock stabilized

1.69

• Debug info removed from build scripts

1.68

• Spare registry support stabilized, but not on by default

1.67

• #[must_use] passes through async fn output
• crossbeam-channel merged into std::sync::mpsc

1.66

• black_box hint function for benchmarking
• Explicit values for enums
• Inclusive ranges ..=4 in match patterns

1.65

• Generics in associated types
• let else syntax
• break from labeled blocks
• split debuginfo on linux from binary
• backtrace API stabilized

1.64

• IntoFuture trait to simplify async APIs
• More FFI types
• rust-analyzer available via rustup
• Cargo can inherit packages from workspaces, and build multiple archs at once

1.63

• Scoped threads
• Const sync primitives (mutex/rwlock/condvar)
• Removal of old lexical borrow checker

1.62.1

• Unsoundness fix with some async fn and impl Trait return types
• Security fix for Intel SGX

1.62

• cargo add command now built-in
• Enums variants can now have #[default]
• Mutexes faster on Linux
• total_cmp for f32 and f64

1.61

• fn main can return custom exit codes via new Termination trait
• Yet more const fn things
• std::io::stdout().lock() works without needing intermediate variable

1.60

• LLVM-based coverage stabilized
• Build timings stablized (cargo build --timings)
• New syntax for cargo features
• Incremental compilation re-enabled by default

1.59

• Incremental compilation disabled by default again
• Inline assembly
• Destructuring in assignments, [c, .., d, _] = [1, 2, 3, 4, 5]; etc
• Stripping of (all) debug symbols stablized in Cargo

1.58.1

• Security fix for race condition with std::fs::remove_dir_all and symlinks

1.58

• 2021 edition: Format strings can capture args from current scope, e.g let a = "example"; let shorter = format!("{a}!");
• -C strip argument to remove debug symbols from standard library

1.57

Announcement

• Some tweaks to macros (#derive combined with cfg() and allows curly braces in expressions)
• Custom named profiles in Cargo
• Failable try_reserve for vec/string/hashmap/etc

1.56

Announcement

• Rust 2021 edition
• Disjount capture, only necessary fields ad captured by closures
• New resolver, panic takes format string same as println

1.55

• Open for ranges, match x { 0 => {}, 1..{} }
• Cargo de-duplicates warnings when running tests

1.54

Annoucement

• Incremental complication is re-enabled (disabled in 1.52.1)
• Macros can be nested inside built-in macros
• SIMD support in WebAssembly

1.53

• Unicode idenfifiers
• "or patterns" inside matches, e.g match ... { Some(1) | Some(2) => ... }
• Cargo handles repos where default HEAD branch is not master
• Authors field no longer included by default

1.52

Including 1.52.1

• Disabled incremental compilation due to bug

1.51

• const generics

1.50

• Lots of methods made const

1.49

• Nothing too much - some stuff with unions and enums

1.48

• Rustdoc intra-doc links and #[doc(alias = "...")] aliases