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use std::mem::transmute;
#[derive(Copy, Clone, PartialEq, PartialOrd, Debug, Hash)]
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 { transmute((i as u8) & 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
}
}