Error code E0597
This error occurs because a value was dropped while it was still borrowed.
Erroneous code example:
#![allow(unused)] fn main() { struct Foo<'a> { x: Option<&'a u32>, } let mut x = Foo { x: None }; { let y = 0; x.x = Some(&y); // error: `y` does not live long enough } println!("{:?}", x.x); }
Here, y
is dropped at the end of the inner scope, but it is borrowed by
x
until the println
. To fix the previous example, just remove the scope
so that y
isn't dropped until after the println
#![allow(unused)] fn main() { struct Foo<'a> { x: Option<&'a u32>, } let mut x = Foo { x: None }; let y = 0; x.x = Some(&y); println!("{:?}", x.x); }