Error code E0381

It is not allowed to use or capture an uninitialized variable.

Erroneous code example:

fn main() {
    let x: i32;
    let y = x; // error, use of possibly-uninitialized variable
}

To fix this, ensure that any declared variables are initialized before being used. Example:

fn main() {
    let x: i32 = 0;
    let y = x; // ok!
}