+/// Overloads of bitwise operators between a Bitboard and a Square for testing
+/// whether a given bit is set in a bitboard, and for setting and clearing bits.
+
+inline Bitboard operator&( Bitboard b, Square s) { return b & square_bb(s); }
+inline Bitboard operator|( Bitboard b, Square s) { return b | square_bb(s); }
+inline Bitboard operator^( Bitboard b, Square s) { return b ^ square_bb(s); }
+inline Bitboard& operator|=(Bitboard& b, Square s) { return b |= square_bb(s); }
+inline Bitboard& operator^=(Bitboard& b, Square s) { return b ^= square_bb(s); }
+
+inline Bitboard operator&(Square s, Bitboard b) { return b & s; }
+inline Bitboard operator|(Square s, Bitboard b) { return b | s; }
+inline Bitboard operator^(Square s, Bitboard b) { return b ^ s; }
+
+inline Bitboard operator|(Square s, Square s2) { return square_bb(s) | s2; }
+
+constexpr bool more_than_one(Bitboard b) {