leo/docs/error-guides/parser/let_mut_statement.md

let mut is deprecated

Example

This error occurs when a variable declaration is marked with mut.

Erroneous code example:

function main() {
    let mut x = 0;
}

The compiler will reject this code with, for example...:

Error [EPAR0370015]: let mut = ... is deprecated. `let` keyword implies mutabality by default.
    --> test.leo:2:5
     |
   2 |     let mut x = 0;
     |     ^^^^^^^

Solution

As the mut modifier is implicitly assumed, the solution is to remove the mut modifier:

function main() {
    let x = 0;
}