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# Error code E0595

#### Note: this error code is no longer emitted by the compiler.

Closures cannot mutate immutable captured variables.

Erroneous code example:

    #![allow(unused)]
    fn main() {
    let x = 3; // error: closure cannot assign to immutable local variable `x`
    let mut c = || { x += 1 };
    }

Make the variable binding mutable:

    #![allow(unused)]
    fn main() {
    let mut x = 3; // ok!
    let mut c = || { x += 1 };
    }