重载operator << operator ==和operator！=

Question

Homework assignment

Have to overload both the operator<<, operator== and operator!=

.h file and .cpp file is included below:

namespace JoePitz
{
   class Complex
   {
      // declare friend functions
      friend ostream &operator<<(ostream &out, const Complex &value);
      friend ostream &operator<<(ostream &out, const bool &value);
      friend istream &operator>>(istream &in, Complex &value);

      public:
         // constructor
     Complex(double real, double imaginary);

      // overloading +/-/==/!= operators
      Complex operator+(const Complex &compx2);
      Complex operator-(const Complex &compx2);
      bool operator==(const Complex &compx2);
      bool operator!=(const Complex &compx2);

      private:
      double real;
      double imaginary;
      void initialize(double real, double imaginary);
   };

      // GCC requires friend functions to be declared in name space
      ostream &operator<<(ostream &out, const Complex &value);
      ostream &operator<<(ostream &out, const bool &value);
      istream &operator>>(istream &in, Complex &value);
}

   excerpt from .cpp file

   ostream& JoePitz::operator<<(ostream &out, const Complex &value)
   {
      // print real
      cout << value.real;

     // print imaginary
     if (value.imaginary == ISZERO)
     {
        cout << POSSIGN << value.imaginary << IMAGNSGN;
     }
     else if (value.imaginary > ISZERO)
     {
        cout << POSSIGN << value.imaginary << IMAGNSGN;
     }
     else
     {
        cout << value.imaginary << IMAGNSGN;
     }

     return out;

  }

  ostream& JoePitz::operator<<(ostream &out, const bool &value)
  {
     return out;
  }

  // overloaded == operator
  bool JoePitz::Complex::operator==(const Complex &compx2)
  {
     return (this->real == compx2.real && this->imaginary == compx2.imaginary);
  }

  // overloaded != operator
  bool JoePitz::Complex::operator!=(const Complex &compx2)
  {
     return !(this->real == compx2.real && this->imaginary == compx2.imaginary);
  }

I received the following compile error:

../src/hw4.cpp:71: error: no match for 'operator<<' in 'c1 << " * * *\\012"' ../src/Complex.h:54: note: candidates are: std::ostream& JoePitz::operator<<(std::ostream&, const bool&) ../src/Complex.h:53: note: std::ostream& JoePitz::operator<<(std::ostream&, const JoePitz::Complex&)

From my understanding this is a result from not knowing which overloaded function to implement.

The problem I am having is how to deal with the fact that the operator<< function return an ostream and accepts a Complex object, but the operator== function return a bool.

But I do not know how to change the operator== function to handle the bool and or the Complex object. I have attempted to add another overloaded opperator<< function that return a bool but the compiler still has problems with it.

Any assistance will be greatly appreciated.

Answer 1

It's a simple operator precedence error, this

cout << "* * * Unit Test 3 comparison operations == != * * \n";
cout << " * * Print c1 == c1 = " << c1 == c1 << " * * *\n";

should be this

cout << "* * * Unit Test 3 comparison operations == != * * \n";
cout << " * * Print c1 == c1 = " << (c1 == c1) << " * * *\n";

<< has higher precedence than == so you need the brackets.

Remove the ostream bool overload.

Another change

  Complex operator+(const Complex &compx2);
  Complex operator-(const Complex &compx2);
  bool operator==(const Complex &compx2);
  bool operator!=(const Complex &compx2);

should all be const methods

  Complex operator+(const Complex &compx2) const;
  Complex operator-(const Complex &compx2) const;
  bool operator==(const Complex &compx2) const;
  bool operator!=(const Complex &compx2) const;