Rust 1.40 adds a feature that stops consumers matching on structs or enums exhaustively, so extending them is not a breaking change!
There's a cute todo!() macro too.
https://blog.rust-lang.org/2019/12/19/Rust-1.40.0.html
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One cute feature of markdown I'd not noticed before: there's no syntax for images *without* a description (i.e. alt text).
https://spec.commonmark.org/0.31.2/#images
I really like pattern matching in Rust, but I find myself using it less and less.
`if let` and `let ... else` require substantially less indentation, and I often use them for Option values.
I don't miss this syntactic sugar in OCaml though. Maybe it's just because OCaml has a 2 space indent, unlike Rust's 4 space indent?
A cute systemd feature to get the system clock roughly correct: if the system time is before the compilation time of the systemd binary, it moves the clock forward to that time!
https://lwn.net/Articles/714355/