GenCrossSection.h

#ifndef HEPMC_GEN_CROSS_SECTION_H
#define HEPMC_GEN_CROSS_SECTION_H

//--------------------------------------------------------------------------
// garren@fnal.gov, May 2009
// 
//--------------------------------------------------------------------------

#include <iostream>

namespace HepMC {


class GenCrossSection {

public:
  GenCrossSection()
    : m_cross_section(0),
      m_cross_section_error(0),
      m_is_set(false)
    {}
  ~GenCrossSection() {}

  GenCrossSection( GenCrossSection const & orig ); 

  void swap( GenCrossSection & other); 
  GenCrossSection &  operator = ( GenCrossSection const & rhs ); 
  bool         operator==( const GenCrossSection& ) const;
  bool         operator!=( const GenCrossSection& ) const;


  // ---  accessors:

  double cross_section()          const { return m_cross_section; }
  double cross_section_error()    const { return m_cross_section_error; }

  bool   is_set()                 const { return m_is_set; }

  // ---  mutators:
  void   set_cross_section( double xs, double xs_err );
  void   set_cross_section( double );
  void   set_cross_section_error( double );
  void   clear();
 
  // ---  I/O:
  std::ostream &  write( std::ostream & ) const;
  std::istream &  read( std::istream & );

private: // data members
    double m_cross_section;
    double m_cross_section_error;
    bool   m_is_set;

};

//
// streaming I/O

inline std::ostream & operator << ( std::ostream & os, GenCrossSection & xs )
{ return xs.write(os); }

inline std::istream & operator >> ( std::istream & is, GenCrossSection & xs )
{ return xs.read(is); }

//
// inline methods

inline void GenCrossSection::set_cross_section( double xs, double xserr ) { 
  set_cross_section(xs);
  set_cross_section_error(xserr); 
}

inline void GenCrossSection::set_cross_section( double xs )        
{
  m_cross_section = xs;
  m_is_set = true;
}

inline void GenCrossSection::set_cross_section_error( double xserr )  
{
  m_cross_section_error = xserr;
}

} // HepMC

#endif  // HEPMC_GEN_CROSS_SECTION_H