JZero.cc

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#include <iostream>
#include <iomanip>

#include "JMath/JZero.hh"

#include "Jeep/JParser.hh"
#include "Jeep/JMessage.hh"


namespace {

  struct __A__ {
    /**
     * Default constructor.
     */
    __A__() :
      a(0)
    {}

    /**
     * Constructor.
     *
     * \param  a             value
     */
    __A__(double a)
    {
      this->a = a;
    }

    /**
     * Equals operator.
     *
     * \param  first         first  value
     * \param  second        second value
     * \return               true if first and second value are equal; else false
     */
    friend inline bool operator==(const __A__& first, const __A__& second)
    {
      return first.a == second.a;
    }
    
    /**
     * Write object to output.
     *
     * \param  out           output stream
     * \param  object        object
     * \return               output stream
     */
    friend inline std::ostream& operator<<(std::ostream& out, const __A__& object)
    {
      return out << object.a;
    }

    double a;
  };
  
  /**
   * Test equaliilty.
   *
   * \param  zero          zero value
   * \return               true if JMath::zero equals given zero value; else false
   */
  template<class T>
  bool inline is_equal(const T& zero)
  {
    T value = JMATH::zero;

    return value == zero;
  }
  
  /**
   * Print class and zero value.
   *
   * \param  out           output stream
   * \param  name          class name
   */
  template<class T>
  inline void print(std::ostream& out, const char* name)
  {
    using namespace std;
    
    T value = JMATH::zero;
    
    out << setw(12) << left << name << ' ' << value << endl;
  }

#define PRINT(OUT, CLASS) print<CLASS>(OUT, #CLASS)
}


/**
 * \file
 *
 * Example program to test zero values (JMATH::zero).
 * \author mdejong
 */
int main(int argc, char**argv)
{
  using namespace std;

  int    debug;

  try {

    JParser<> zap("Example program to test zero values of non-primitive data types.");

    zap['d'] = make_field(debug)          = 3;

    zap(argc, argv);
  }
  catch(const exception &error) {
    FATAL(error.what() << endl);
  }

  using namespace JPP;

  PRINT(cout, int);
  PRINT(cout, float);
  PRINT(cout, double);
  PRINT(cout, __A__);

  ASSERT(is_equal<int>   (0));
  ASSERT(is_equal<float> (0.0));
  ASSERT(is_equal<double>(0.0));
  ASSERT(is_equal<__A__> (__A__(0)));
  
  return 0;
}