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## borrow box
### Instructions
Game time.
You will implement some **CRUD** functionality for a game session. You will need to implement the `GameSession` structure with the following associated functions:
- `new`: which initializes a game session state with player names and some other information. This function returns the structure wrapped in a `Box`.
- `read_winner`: which returns a tuple with the name and score of the player who is currently winning. In the case that no player is winning, it should return the same tuple with the string `"Same score! tied"` and the tied score.
- `update_score`: which receives the name of a player, and increments their score. The `nbr_of_games` should also be incremented. This function should **do nothing** if the the game session is already finished.
- `delete`: which takes ownership of the boxed game session and returns a string: `"game deleted: id -> 0"`.
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> If `nbr_of_games` is 5, then it is "best out of 5", and no more than 5 games can be played. If some player has a score of 3, then the game session is also finished. This is because there is an insufficient number of remaining games for the trailing player to catch up.
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### Expected Functions
```rust
#[derive(Debug, Clone, Eq, PartialEq)]
pub struct GameSession {
pub id: u32,
pub p1: (String, u16),
pub p2: (String, u16),
pub nbr_of_games: u16
}
impl GameSession {
pub fn new(i: u32, pl1: String, pl2: String, n: u16) -> Box<GameSession> {
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}
pub fn read_winner(&self) -> (String, u16) {
}
pub fn update_score(&mut self, user_name: String) {
}
pub fn delete(self) -> String {
}
}
```
### Usage
4 years ago
Here is a program to test your functions,
```rust
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use borrow_box::*;
fn main() {
let mut game = GameSession::new(0, String::from("Joao"), String::from("Susana"), 5);
println!("{:?}", game.read_winner());
// output : ("Same score! tied", 0)
game.update_score(String::from("Joao"));
game.update_score(String::from("Joao"));
game.update_score(String::from("Susana"));
game.update_score(String::from("Susana"));
println!("{:?}", game.read_winner());
// output : ("Same score! tied", 2)
game.update_score(String::from("Joao"));
// this one will not count because it already 5 games played, the nbr_of_games
game.update_score(String::from("Susana"));
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println!("{:?}", game.read_winner());
// output : ("Joao", 3)
println!("{:?}", game.delete());
// output : "game deleted: id -> 0"
// game.read_winner();
// this will give error
// because the game was dropped, no longer exists on the heap
}
```
And its output:
```console
$ cargo run
("Same score! tied", 0)
("Same score! tied", 2)
("Joao", 3)
"game deleted: id -> 0"
$
```
### Notions
- [Box Pointers](https://doc.rust-lang.org/book/ch15-01-box.html)