rustdoku/src/lib.rs

#[derive(Clone, Debug, Copy)]
pub enum CellValue {
    One,
    Two,
    Three,
    Four,
    Five,
    Six,
    Seven,
    Eight,
    Nine,
}

pub struct Cell {
    value: Option<CellValue>,
    candidates: Vec<CellValue>,
}

impl Default for Cell {
    fn default() -> Cell {
        Cell {
            value: None,
            candidates: vec![
                CellValue::One,
                CellValue::Two,
                CellValue::Three,
                CellValue::Four,
                CellValue::Five,
                CellValue::Six,
                CellValue::Seven,
                CellValue::Eight,
                CellValue::Nine,
            ],
        }
    }
}

#[derive(Default)]
pub struct Board {
    cells: [[Cell; 9]; 9],
}

impl Board {
    fn value(self, x: usize, y: usize) -> Option<CellValue> {
        self.cells[x][y].value
    }
}

pub fn add(left: u64, right: u64) -> u64 {
    left + right
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn it_works() {
        let result = add(2, 2);
        assert_eq!(result, 4);
    }
}