Rust Programming Cookbook

How to do it...

Follow these steps to explore enums:

1. Create a new project with cargo new enums --lib and open this folder in Visual Studio Code, or any IDE of your choosing.
2. Open src/lib.rs and declare an enum containing some data:

use std::io;pub enum ApplicationError {    Code { full: usize, short: u16 },    Message(String),    IOWrapper(io::Error),    Unknown}

3. In addition to the declaration, we also implement a simple function:

impl ApplicationError {    pub fn print_kind(&self, mut to: &mut impl io::Write) ->     io::Result<()> {        let kind = match self {            ApplicationError::Code { full: _, short: _ } => "Code",            ApplicationError::Unknown => "Unknown",            ApplicationError::IOWrapper(_) => "IOWrapper",            ApplicationError::Message(_) => "Message"        }; write!(&mut ...