Option and Result types - Rust for C-Programmers

10.9 Enums as the Basis for `Option` and `Result`

The Rust standard library relies heavily on enums. Two crucial examples are Option and Result.

10.9.1 The `Option` Enum

#![allow(unused)]
fn main() {
enum Option<T> {
    Some(T),
    None,
}
}

No Null Pointers: Option<T> encodes the possibility of either having a value (Some) or not (None).
Pattern Matching: Forces you to handle the absence of a value explicitly.

10.9.2 The `Result` Enum

#![allow(unused)]
fn main() {
enum Result<T, E> {
    Ok(T),
    Err(E),
}
}

Error Handling: Distinguishes success (Ok) from failure (Err).
Pattern Matching: Encourages explicit error handling.

We’ll discuss these types further when covering optional values and error handling in Chapters 14 and 15.