Utilities/interface/Sgn.h

0001 #ifndef PhysicsTools_Utilities_Sgn_h
0002 #define PhysicsTools_Utilities_Sgn_h
0003
0004 namespace funct {
0005
0006   template <typename T>
0007   struct SgnStruct {
0008     SgnStruct(const T& t) : _(t) {}
0009     inline double operator()() const { return _() >= 0 ? 1 : -1; }
0010     inline operator double() const { return _() >= 0 ? 1 : -1; }
0011     T _;
0012   };
0013
0014   template <typename T>
0015   struct Sgn {
0016     typedef SgnStruct<T> type;
0017     inline static type compose(const T& t) { return type(t); }
0018   };
0019
0020   template <typename T>
0021   inline typename Sgn<T>::type sgn(const T& t) {
0022     return Sgn<T>::compose(t);
0023   }
0024
0025 }  // namespace funct
0026
0027 #endif