What it does

If an assignment dominate all usages where it can reach, assignment can be replaced by a let bind, instead of overwrite

Advantage

• less mut
• like functional programming
• explicit dominance
• helpful in jumpping to definition in ide

Drawbacks

None (not sure)

Example

 let mut x = "hello".to_string();
    let mut y = vec![];

    y.push(x);

    x = "goodbye".to_string();

    println!("{}", x); 

Could be written as:

 let mut x = "hello".to_string();
    let mut y = vec![];

    y.push(x);

    let x = "goodbye".to_string();

    println!("{}", x);