变量绑定在默认情况下是不可变的, 但是这可以使用 mut
修辞符来覆盖。
fn main() { |
let _immutable_binding = 1; |
let mut mutable_binding = 1; |
println!("Before mutation: {}", mutable_binding); |
// Ok |
mutable_binding += 1; |
println!("After mutation: {}", mutable_binding); |
// Error! |
_immutable_binding += 1; |
// FIXME ^ Comment out this line |
} |