https://blog.rust-lang.org/2017/03/16/Rust-1.16.html "The largest addition to Rust 1.16 is cargo check. This new subcommand should speed up the development workflow in many cases." Мощно: "When slicing a &str, you’ll see better errors. For example, this code: &"abcαβγ"[..4] Is incorrect. It generates this error: thread 'str::test_slice_fail_boundary_1' panicked at 'byte index 4 is not a char boundary; it is inside 'α' (bytes 3..5) of `abcαβγ`' The part after the ; is new."