Utilities/interface/SimplifyNumerical.h

0001 #ifndef PhysicsTools_Utilities_SimplifyNumerical_h
0002 #define PhysicsTools_Utilities_SimplifyNumerical_h
0003 #include "PhysicsTools/Utilities/interface/Fraction.h"
0004 #include "PhysicsTools/Utilities/interface/Numerical.h"
0005 #include "PhysicsTools/Utilities/interface/Operations.h"
0006
0007 namespace funct {
0008
0009   template <int n, int m>
0010   struct Sum<Numerical<n>, Numerical<m> > {
0011     typedef Numerical<n + m> type;
0012     inline static type combine(const Numerical<n>&, const Numerical<m>&) { return type(); }
0013   };
0014
0015   template <int n, int m>
0016   struct Difference<Numerical<n>, Numerical<m> > {
0017     typedef Numerical<n - m> type;
0018     inline static type combine(const Numerical<n>&, const Numerical<m>&) { return type(); }
0019   };
0020
0021   template <int n>
0022   struct Minus<Numerical<n> > {
0023     typedef Numerical<-n> type;
0024     inline static type operate(const Numerical<n>&) { return type(); }
0025   };
0026
0027   template <int n, int m>
0028   struct Product<Numerical<n>, Numerical<m> > {
0029     typedef Numerical<n * m> type;
0030     inline static type combine(const Numerical<n>&, const Numerical<m>&) { return type(); }
0031   };
0032
0033   template <int n>
0034   struct Ratio<Numerical<n>, Numerical<1> > {
0035     typedef Numerical<n> type;
0036     inline static type combine(const Numerical<n>&, const Numerical<1>&) { return type(); }
0037   };
0038
0039   // n ^ m = n * n ^ ( m - 1 )
0040   template <int n, int m, bool posM = (m > 0)>
0041   struct NumPower {
0042     typedef Numerical<n * NumPower<n, m - 1>::type::value> type;
0043     inline static type combine(const Numerical<n>&, const Numerical<m>&) { return type(); }
0044   };
0045
0046   // 1 ^ m = 1
0047   template <int m, bool posM>
0048   struct NumPower<1, m, posM> {
0049     typedef Numerical<1> type;
0050     inline static type combine(const Numerical<1>&, const Numerical<m>&) { return type(); }
0051   };
0052
0053   // n ^ 1 = n
0054   template <int n>
0055   struct NumPower<n, 1, true> {
0056     typedef Numerical<n> type;
0057     inline static type combine(const Numerical<n>&, const Numerical<1>&) { return type(); }
0058   };
0059
0060   // n ^ 0 = 1
0061   template <int n>
0062   struct NumPower<n, 0, true> {
0063     typedef Numerical<1> type;
0064     inline static type combine(const Numerical<n>&, const Numerical<0>&) { return type(); }
0065   };
0066
0067   // n ^ (-m) = 1 / n ^ m
0068   template <int n, int m>
0069   struct NumPower<n, m, false> {
0070     typedef typename Fraction<1, NumPower<n, -m>::type::value>::type type;
0071     inline static type combine(const Numerical<n>&, const Numerical<m>&) { return type(); }
0072   };
0073
0074   template <int n, int m>
0075   struct Power<Numerical<n>, Numerical<m> > : public NumPower<n, m> {};
0076
0077 }  // namespace funct
0078
0079 #endif