7. Binary member operator syntax

• 
      // rational.h
      class Rational {
      private:
          int m_n;
          int m_d;
      public:
          // Member binary operator
          bool operator==( Rational const& other) const;
      };
  
      // rational.cpp
      bool Rational::operator==( Rational const& other ) const
      {
          // This way, 1/2 == 2/4 (should it?)
          return ( ( m_n * other.m_d ) == ( m_d * other.m_n ) );
      }