inline Score operator+ (const Score d1, const Score d2) { return Score(int(d1) + int(d2)); }
inline Score operator- (const Score d1, const Score d2) { return Score(int(d1) - int(d2)); }
inline Score operator* (int i, const Score d) { return Score(i * int(d)); }
inline Score operator+ (const Score d1, const Score d2) { return Score(int(d1) + int(d2)); }
inline Score operator- (const Score d1, const Score d2) { return Score(int(d1) - int(d2)); }
inline Score operator* (int i, const Score d) { return Score(i * int(d)); }