TryFrom/TryInto 第四题 答案报错, 答案有问题

[LukerSpringtree]

https://zh.practice.rs/type-conversions/from-into.html#tryfromtryinto

fn main() {
    let n: i16 = 256;

    let n: u8 = match n.try_into() {
        Ok(n) => n,
        Err(e) => {
            println!("there is an error when converting: {:?}, but we catch it", e.to_string());
            0
        }
    };

    assert_eq!(n, 0);

    println!("Success!")
}

报错如下：

error[E0599]: no method named `try_into` found for type `i16` in the current scope
   --> main.rs:4:25
    |
4   |     let n: u8 = match n.try_into() {
    |                         ^^^^^^^^ method not found in `i16`
    |
   ::: C:\Users\lde1wx\.rustup\toolchains\stable-x86_64-pc-windows-msvc\lib/rustlib/src/rust\library\core\src\convert\mod.rs:569:8
    |
569 |     fn try_into(self) -> Result<T, Self::Error>;
    |        -------- the method is available for `i16` here
    |
    = help: items from traits can only be used if the trait is in scope
    = note: 'std::convert::TryInto' is included in the prelude starting in Edition 2021
help: the following trait is implemented but not in scope; perhaps add a `use` for it:
    |
1   + use std::convert::TryInto;
    |

error: aborting due to previous error

For more information about this error, try `rustc --explain E0599`.

rustc 1.74.0 (79e9716c9 2023-11-13)