// +build go1.9

package chess

import "math/bits"

// Reverse returns a bitboard where the bit order is reversed.
func (b bitboard) Reverse() bitboard {
	return bitboard(bits.Reverse64(uint64(b)))
}

// Occupied returns true if the square's bitboard position is 1.
func (b bitboard) Occupied(sq Square) bool {
	return (bits.RotateLeft64(uint64(b), int(sq)+1) & 1) == 1
}