Rust Core

Ownership and borrowing

Beginner·24 min read

Rust associates each value with an owner. When ownership moves, the previous binding can no longer use the value unless the type implements Copy or a borrow is created.

rust

fn length(value: &String) -> usize {
    value.len()
}

fn main() {
    let name = String::from("LaySoftware");
    println!("{}", length(&name));
    println!("{}", name);
}

Mental model

Ask: who owns this value, how long must it live, and can I borrow it immutably or mutably at this point?

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