1.26.0 #

Released on: 10 May, 2018
Branched from master on: 23 March, 2018

Language #

Closures now implement Copy and/or Clone if all captured variables implement either or both traits.
The inclusive range syntax e.g. for x in 0..=10 is now stable.
The '_ lifetime is now stable. The underscore lifetime can be used anywhere a lifetime can be elided.
impl Trait is now stable allowing you to have abstract types in returns or in function parameters. E.g. fn foo() -> impl Iterator<Item=u8> or fn open(path: impl AsRef<Path>).
Pattern matching will now automatically apply dereferences.
128-bit integers in the form of u128 and i128 are now stable.
main can now return Result<(), E: Debug> in addition to ().
A lot of operations are now available in a const context. E.g. You can now index into constant arrays, reference and dereference into constants, and use tuple struct constructors.

Fixed entry slice patterns are now stable. E.g.

let points = [1, 2, 3, 4];
match points {
    [1, 2, 3, 4] => println!("All points were sequential."),
    _ => println!("Not all points were sequential."),
}

Compiler #

LLD is now used as the default linker for wasm32-unknown-unknown.
Fixed exponential projection complexity on nested types. This can provide up to a ~12% reduction in compile times for certain crates.
Added the --remap-path-prefix option to rustc. Allowing you to remap path prefixes outputted by the compiler.
Added powerpc-unknown-netbsd target.

Libraries #

Stabilized APIs #

Cargo #

Misc #

The second edition of “The Rust Programming Language” book is now recommended over the first.

Compatibility Notes #

aliasing a Fn trait as dyn no longer works. E.g. the following syntax is now invalid.
```
use std::ops::Fn as dyn;
fn g(_: Box<dyn(std::fmt::Debug)>) {}
```

The result of dereferences are no longer promoted to 'static. e.g.

fn main() {
    const PAIR: &(i32, i32) = &(0, 1);
    let _reversed_pair: &'static _ = &(PAIR.1, PAIR.0); // Doesn't work
}

Deprecate AsciiExt trait in favor of inherent methods.
".e0" will now no longer parse as 0.0 and will instead cause an error.
Removed hoedown from rustdoc.
Bounds on higher-kinded lifetimes a hard error.