u/JustJeffrey

I'm trying to program a simple chess engine and I wanted an easy way to convert an enum into a number and vice versa. For the first case it seemed simple enough, I could just do as usize, but for the second it seemed more complicated. This is the implementation I ended up with:

#[derive(Copy, Clone, Debug)]
pub enum Piece {
    Pawns,
    Knights,
    Bishops,
    Rooks,
    Queens,
    King,
}


impl TryFrom<usize> for Piece {
    type Error = String;
    fn try_from(value: usize) -> Result<Self, Self::Error> {
        if value <= 5 {
            Ok(unsafe { std::mem::transmute::<u8, Piece>(value as u8) })
        } else {
            Err("Invalid value for Piece".to_string())
        }
    }
}

It seems to work, but I was wondering if it's a good idea? Is it going to give me problems down the line?