Rust enum implement += 1 - rust

Question

I try to write Minesweeper
I have enum with status of cell and trying to write function to recognize how much mines around it.
enum CellStatus {
CLOSED,
MINED,
FLAGED,
OPENED,
ONE,
TWO,
THREE,
FOUR,
FIVE,
SIX,
SEVEN,
EIGHT
}
if mine_area[i+1][j+1] == CellStatus::MINED {
mine_area[i][j] += 1;
}
This is what compiler advice me:
error[E0368]: binary assignment operation `+=` cannot be applied to type `CellStatus`
--> src/main.rs:25:9
|
25 | mine_area[i][j] += 1;
| ---------------^^^^^
| |
| cannot use `+=` on type `CellStatus`
|
note: an implementation of `AddAssign<_>` might be missing for `CellStatus`
--> src/main.rs:126:1
|
126 | enum CellStatus {
| ^^^^^^^^^^^^^^^ must implement `AddAssign<_>`
note: the following trait must be implemented
On offical AddAssign it is example for Point, and it struct not enum.
BrownieInMotion advised me to use u8 in Opened, it's really helpful, but not a solution to a problem.

Answer 1

What about using an enum like this instead?
enum Status {
Closed,
Flagged,
Mined,
Opened(u8),
}
However, I am a bit confused about how the mine state is held. I think it makes sense to use this when representing how mines should be displayed, but I see that you are also using this enum to hold the board state itself.
if mine_area[i+1][j+1] == CellStatus::MINED
I don't think this check makes sense because this enum is not suited for representing the state of the board; it's better for representing how the board should be drawn.
For example, a cell with a mine can be flagged or not flagged, but the enum can only represent one of these traits at a time.

Answer 2

Here is how to do it correct:
impl AddAssign for Status {
fn add_assign(&mut self, other: Self) {
*self = match *self {
Status::Opened(count) => match other {
Status::Opened(count2) => Status::Opened(count + count2),
_ => other,
},
_ => other
}
}
}
My final implementation is:
use std::ops::AddAssign;
fn main() {
let width:u16 = 5;
let heigh:u16 = 5;
let mut game_area = vec![vec![Status::Closed; width.into()]; heigh.into()];
game_area[1][1] = Status::Opened(0);
game_area[1][1] += Status::Opened(1);
game_area[1][1] += Status::Opened(1);
game_area[1][1] += Status::Opened(1);
println!("{}", game_area[1][1].as_str());
}
#[derive(Clone)]
enum Status {
Closed,
Flagged,
Mined,
Opened(u8),
}
const MINE_CHAR: [&str; 9] = ["🔳", "1️⃣", "2️⃣", "3️⃣", "4️⃣", "5️⃣", "6️⃣", "7️⃣", "8️⃣"];
impl Status {
pub fn as_str(&self) -> String {
match self {
Status::Mined => "💣".to_string(),
Status::Closed => "⬜".to_string(),
Status::Flagged => "🚩".to_string(),
Status::Opened(i) => MINE_CHAR[*i as usize].to_string()
}}
}
impl AddAssign for Status {
fn add_assign(&mut self, other: Self) {
*self = match *self {
Status::Opened(count) => match other {
Status::Opened(count2) => Status::Opened(count + count2),
_ => other,
},
_ => other
}
}
}