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#[derive(Copy, Clone, PartialEq, PartialOrd)]
pub enum Rank {
First,
Second,
Third,
Fourth,
Fifth,
Sixth,
Seventh,
Eighth,
}
pub const NUM_RANKS: usize = 8;
pub const ALL_RANKS: [Rank; NUM_RANKS] = [Rank::First, Rank::Second, Rank::Third, Rank::Fourth, Rank::Fifth, Rank::Sixth, Rank::Seventh, Rank::Eighth];
impl Rank {
pub fn from_index(i: usize) -> Rank {
unsafe {
*ALL_RANKS.get_unchecked(i & 7)
}
}
pub fn down(&self) -> Rank {
Rank::from_index(self.to_index().wrapping_sub(1))
}
pub fn up(&self) -> Rank {
Rank::from_index(self.to_index() + 1)
}
pub fn to_index(&self) -> usize {
*self as usize
}
}