Practical Site Reliability Engineering

Borrowing values in Rust

Owned values can be borrowed in Rust to allow them to be used for a certain period of time. Borrows can be nested, and borrowed values can become owned values through cloning (using a command such as v.clone).

The following code snippet shows an example of borrowing. The & symbol means borrowed reference:

fn helper(slot: &Vec<int> { /* ... */ }fn main() {  let a = Vec::new();// doesn't move!  helper(&a);  helper(&a);   }

Borrowed values are only valid for a particular lifetime:

let a: ∫{    let b = 3;    a = &b; // error! 'b' does not live long enough}Let a: ∫let b =3;a = &b; // ok, 'b' has the same lifetime as 'a'