Mutability

Table of Contents

Modern programming languages differ in their attitude towards data mutability.

Where does Rust land?

An Example

fn main() {
    let answer = 42;
    answer = 32;
}

Correct

fn main() {
    let mut answer = 42;
    answer = 32;
}

In Rust data mutability must be declared.

Mutability is always apparent from reading the code.

Mutability is fundamental to Rust and is a common consideration.

Mutability is a property of variables and bindings, not of the bound data!