functors/math2.hpp

The following code example is taken from the book
C++ Templates - The Complete Guide
by David Vandevoorde and Nicolai M. Josuttis, Addison-Wesley, 2002
© Copyright David Vandevoorde and Nicolai M. Josuttis 2002


#include <cmath>
#include <cstdlib>

class Abs {
  public:
    // to fit in the framework:
    enum { NumParams = 1 };
    typedef double ReturnT;
    typedef double Param1T;

    // ``function call'':
    double operator() (double v) const { 
        return std::abs(v); 
    }
};

class Sine {
  public:
    // to fit in the framework:
    enum { NumParams = 1 };
    typedef double ReturnT;
    typedef double Param1T;

    // ``function call'':
    double operator() (double a) const {
        return std::sin(a); 
    }
};