Rust Basics

Installation

Install rustup first. It may be done with standard package manager or any other way. rustup will install rustc rust compiler, cargo and other required tools.

The run rustup component add rust-analyzer to install rust LSP server. And install cargo-nextext - test runner.

Install code-lldb - the debugger for rust.

Never Type

! is an empty type in Rust, which can never be instanciated. It usually used to indicate that function or expression never returns value:

fn func() -> ! {
}

Also it used in match expressions, when continue, panic or similar operation executed in some arm. ! useful here, because all arms should return value of same type and never type helps in this scenario.

let guess: u32 = match guess.trim().parse() {
    Ok(num) => num,
    Err(_) => continue,
};