Rust 1.25.0

Language

• The #[repr(align(x))] attribute is now stable. RFC 1358
• You can now use nested groups of imports. e.g. use std::{fs::File, io::Read, path::{Path, PathBuf}};
• You can now have | at the start of a match arm. e.g.

enum Foo { A, B, C }

fn main() {
    let x = Foo::A;
    match x {
        | Foo::A
        | Foo::B => println!("AB"),
        | Foo::C => println!("C"),
    }
}

Compiler

• Upgraded to LLVM 6.
• Added -C lto=val option.
• Added i586-unknown-linux-musl target

Libraries

• Impl Send for process::Command on Unix.
• Impl PartialEq and Eq for ParseCharError.
• UnsafeCell::into_inner is now safe.
• Implement libstd for CloudABI.
• Float::{from_bits, to_bits} is now available in libcore.
• Implement AsRef<Path> for Component
• Implemented Write for Cursor<&mut Vec<u8>>
• Moved Duration to libcore.

Stabilized APIs

• Location::column
• ptr::NonNull

The following functions can now be used in a constant expression. eg. static MINUTE: Duration = Duration::from_secs(60);

• Duration::new
• Duration::from_secs
• Duration::from_millis

Cargo

• cargo new no longer removes rust or rs prefixes/suffixes.
• cargo new now defaults to creating a binary crate, instead of a library crate.

Misc

• Rust by example is now shipped with new releases

Compatibility Notes

• Deprecated net::lookup_host.
• rustdoc has switched to pulldown as the default markdown renderer.
• The borrow checker was sometimes incorrectly permitting overlapping borrows around indexing operations (see #47349). This has been fixed (which also enabled some correct code that used to cause errors (e.g. #33903 and #46095).
• Removed deprecated unstable attribute #[simd].