c++ - 重载 operator<< operator== 和 operator!=

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必须同时重载 operator<<、operator== 和 operator!=

.h文件和.cpp文件如下:

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);
  }

我收到以下编译错误:

../src/hw4.cpp:71: 错误:'c1 << "* * *\012"' 中的 'operator<<' 不匹配../src/Complex.h:54: 注意:候选人是:std::ostream& JoePitz::operator<<(std::ostream&, const bool&)../src/Complex.h:53: 注意:std::ostream& JoePitz::operator<<(std::ostream&, const JoePitz::Complex&)

据我了解，这是因为不知道要实现哪个重载函数。

我遇到的问题是如何处理 operator<< 函数返回一个 ostream 并接受一个 Complex 对象，但 operator== 函数返回一个 bool。

但我不知道如何更改 operator== 函数来处理 bool 和/或 Complex 对象。我试图添加另一个返回 bool 的重载 opperator<< 函数，但编译器仍然有问题。

如有任何帮助，我们将不胜感激。

Answer 1

这是一个简单的运算符优先级错误，这个

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

应该是这样

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

<<优先级高于 ==所以你需要括号。

移除 ostream bool 重载。

另一个变化

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

应该都是常量方法

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