rust_error_handling.md

There are two types of errors:

• Recoverable Errors
• Unrecoverable Errors

Rust uses Result<T, E> for handling recoverable errors and the panic! macro to for unrecoverble errors.

Example

panic!

    panic!("crash and burn");

$ cargo run
   Compiling panic v0.1.0 (file:///projects/panic)
    Finished dev [unoptimized + debuginfo] target(s) in 0.25s
     Running `target/debug/panic`
thread 'main' panicked at 'crash and burn', src/main.rs:2:5
note: Run with `RUST_BACKTRACE=1` for a backtrace.

Result<T, E>

fn read_username_from_file() -> Result<String, io::Error> {
    let mut f = File::open("hello.txt")?;
    let mut s = String::new();
    f.read_to_string(&mut s)?;
    Ok(s)
}