Rust通過靜態類型提供類型安全。變量綁定可以在聲明類型注解的時候。然而，在大多數情況下，編譯器將能夠推斷出變量的類型從上下文，嚴重降低了注解負擔。

值(如文本)可以綁定變量，使用 let 綁定。

fn main() {
    let an_integer = 1u32;
    let a_boolean = true;
    let unit = ();

    // copy `an_integer` into `copied_integer`
    let copied_integer = an_integer;

    println!("An integer: {:?}", copied_integer);
    println!("A boolean: {:?}", a_boolean);
    println!("Meet the unit value: {:?}", unit);

    // The compiler warns about unused variable bindings; these warnings can
    // be silenced by prefixing the variable name with an underscore
    let _unused_variable = 3u32;

    let noisy_unused_variable = 2u32;
    // FIXME ^ Prefix with an underscore to suppress the warning
}