template <class T> inline const T& min(const T& a, const T& b, const T& c) { return min(a, min(b, c)); } template <class T> inline const T& min(const T& a, const T& b, const T& c, const T& d) { return min(min(a, b), min(c, d)); } template <class T> inline const T& max(const T& a, const T& b, const T& c) { return max(a, max(b, c)); } template <class T> inline const T& max(const T& a, const T& b, const T& c, const T& d) { return max(max(a, b), max(c, d)); }