Error Handling

Rust takes a unique approach to error handling — there are no exceptions. Instead, Rust uses the Result<T, E> enum for recoverable errors and panic! for unrecoverable errors. This makes error handling explicit and impossible to ignore.

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Two Kinds of Errors

Kind	Mechanism	Example
Unrecoverable	panic! macro	Index out of bounds, corrupted state
Recoverable	Result<T, E> enum	File not found, invalid input, network timeout

Most errors in Rust are recoverable and should use Result.

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panic! — Unrecoverable Errors

When something goes catastrophically wrong:

fn main() {
    panic!("crash and burn!");
}

When a panic! occurs:

1. The program prints an error message
2. The stack is unwound (by default) and memory is cleaned up
3. The program exits

When Does Rust Panic?

• Calling panic! explicitly
• Array index out of bounds
• Integer overflow in debug mode
• Calling .unwrap() on a None or Err

Tip: Set the environment variable RUST_BACKTRACE=1 to see a full backtrace when a panic occurs.

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Result<T, E> — Recoverable Errors

The Result enum represents either success or failure: