template<PieceType Pt> int count() const;
template<PieceType Pt> const Square* squares(Color c) const;
template<PieceType Pt> Square square(Color c) const;
template<PieceType Pt> int count() const;
template<PieceType Pt> const Square* squares(Color c) const;
template<PieceType Pt> Square square(Color c) const;
// index[from] is not updated and becomes stale. This works as long as index[]
// is accessed just by known occupied squares.
// index[from] is not updated and becomes stale. This works as long as index[]
// is accessed just by known occupied squares.
byTypeBB[ALL_PIECES] ^= fromTo;
byTypeBB[type_of(pc)] ^= fromTo;
byColorBB[color_of(pc)] ^= fromTo;
byTypeBB[ALL_PIECES] ^= fromTo;
byTypeBB[type_of(pc)] ^= fromTo;
byColorBB[color_of(pc)] ^= fromTo;