## check_user_name
### Instructions
Sometimes it is more desirable to catch the failure of some parts of a program instead of just calling panic.
For this exercise you will have to create a tool that manages users' access levels.
You will have to create an `AccessLevel` enum which could be `Guest` , `Normal` , `Admin` .
You will also have to create a `User` struct which has:
- Fields:
- `name` : `String`
- `acessLevel` : `enum`
- Associated functions:
- `new` : which initializes the struct.
- `send_name` : which takes only `self` as argument and returns an `Option<&str>` with `None` if the user is a `Guest` or the `name` if the `AccessLevel` has any of the other options.
- Other functions:
- `check_user_name` : which takes a `User` , calls `send_name` and returns a `tuple` with `true` and the user `name` if `send_name` returns the name or `false` and `"Error: User is guest"` if not.
### Expected Functions and Data Structures
```rust
pub enum AccessLevel {}
pub struct User {}
impl User {
pub fn new(name: String, level: AccessLevel) -> User {}
pub fn send_name(& self) -> Option< & str> {}
}
pub fn check_user_name(user: & User) -> (bool, & str) {}
```
### Usage
Here is a program to test your function:
```rust
use check_user_name::*;
fn main() {
let user0 = User::new("Didier".to_string(), AccessLevel::Admin);
println!("{:?}", check_user_name(&user0));
let user1 = User::new("Mary".to_string(), AccessLevel::Normal);
println!("{:?}", check_user_name(&user1));
let user2 = User::new("John".to_string(), AccessLevel::Guest);
println!("{:?}", check_user_name(&user2));
}
```
And its output:
```console
$ cargo run
(true, "Didier")
(true, "Mary")
(false, "ERROR: User is guest")
$
```
