Ownership

• Each value in Rust has a variable that’s called its owner.
• There can only be one owner at a time.
• When the owner goes out of scope, the value will be dropped.

// this function takes ownership of `v`
fn print_vector(v: Vec<i32>) {
    println!("{:?}", v);

    // `v` is deallocated here
}

fn main() {
    let v = vec![1, 2, 3];

    print_vector(v); // `v` is moved, transferring ownership

    // trying to use `v` here is a compile error
    // v.len();
}

This style of resource management is similar to how RAII types like unique_ptr work in C++.

Unlike C++, Rust does not have move constructors. A move is always just a memcpy.

Simple types like integers can still be used after being moved. This behaviour is controlled by the Copy trait.