Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

#[derive(Debug)]
struct Buffer {
    data: Vec<u8>,
}

// Takes ownership of buf — caller can no longer use it
fn process(buf: Buffer) -> usize {
    println!("processing {} bytes", buf.data.len());
    buf.data.len()
}

// Returns ownership back so the caller can continue using it
fn inspect(buf: Buffer) -> Buffer {
    println!("first byte: {:?}", buf.data.first());
    buf  // move buf back to the caller
}

fn main() {
    let buf = Buffer { data: vec![1, 2, 3, 4, 5] };

// Pass to inspect — ownership goes in and comes back
    let buf = inspect(buf);
    println!("still have buf: {:?}", buf);

// Pass to process — ownership is consumed; buf is gone
    let len = process(buf);
    // println!("{:?}", buf); // compile error: use of moved value
    println!("processed {len} bytes");

// Demonstrate that Vec<u8> is not Copy
    let v1 = vec![10u8, 20, 30];
    let v2 = v1;    // move
    // let _ = v1;  // compile error
    println!("v2 = {:?}", v2);

// Cloning avoids the move
    let v3 = v2.clone();
    println!("v2={:?}  v3={:?}", v2, v3);
}