Rust通过静态类型提供类型安全。变量绑定可以在声明类型注解的时候。然而,在大多数情况下,编译器将能够推断出变量的类型从上下文,严重降低了注解负担。
值(如文本)可以绑定变量,使用 let 绑定。
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 |
} |