OOP Patterns vs Idiomatic Rust

Idiomatic Rust replaces OOP inheritance and mutable shared state with composition, traits, and ownership rules to ensure memory safety without a garbage collector. Instead of defining a class hierarchy with extends, you define a struct for data and a trait for shared behavior, then implement the trait for your struct. Use &self for read-only access and &mut self for mutation, relying on the borrow checker to prevent data races at compile time.

struct Inventory {
    shirts: Vec<String>,
}

trait Giveaway {
    fn most_stocked(&self) -> String;
}

impl Giveaway for Inventory {
    fn most_stocked(&self) -> String {
        // Logic to find most stocked item
        "Blue".to_string()
    }
}

Think of OOP as building a family tree where children inherit traits from parents, while Rust is like a toolbox where you pick specific tools (traits) to attach to different objects (structs) as needed. This approach prevents bugs by ensuring only one part of your code can change data at a time, rather than relying on a runtime system to clean up memory. You describe what an object can do using traits, rather than what it is in a hierarchy.