c++実現複素クラス

主に演算子を再ロードして複数の基本演算を実現する練習です.
複素加算(リロードされた演算子:+、+=、前置++、後置++);
複素減算(リロードされた演算子:-、-=、前置--、後置--);
複素乗算(リロードされた演算子:*、*=、);
複素除算(リロードされた演算子:/、/=、);
コードは次のとおりです.

#include<iostream>
using namespace std;
class Complex
{
public:
 Complex(float real = 1, float imag = 1):_real(real), _imag(imag){}//    
 Complex(const Complex& complex);//      
 ~Complex(){};//    
 Complex& operator=(const Complex& complex);//       
 
 bool operator==(const Complex& complex);
 bool operator!=(const Complex& complex);
 Complex operator+(const Complex& complex);
 Complex& operator++();//  ++
 Complex operator++(int);//  ++
 Complex& operator+=(const Complex& complex);
 Complex operator-(const Complex& complex);
 Complex& operator-=(const Complex& complex);
 Complex& operator--();//  --
 Complex operator--(int);//  --
 Complex operator*(const Complex& complex);
 Complex& operator*=(const Complex& complex);
 Complex operator/(const Complex& complex);
 Complex& operator/=(const Complex& complex);
 friend ostream& operator<<(ostream& output, const Complex& complex);//       
private:
 float _real;
 float _imag;
};

 
各関数の実装:

Complex::Complex(const Complex& complex)//      
{
 _real = complex._real;
 _imag = complex._imag;
}
 
Complex& Complex::operator=(const Complex& complex)//       
{
 cout << "       " << endl;
 if (this != &complex)
 {
  _real = complex._real;
  _imag = complex._imag;
 }
 return *this;
}
 
ostream& operator<<(ostream& output, const Complex& complex)//       
{
  output << "(" << complex._real;
 if (complex._imag >= 0)
 {
  output << "+";
 }
 output << complex._imag << "i)";
  return output;
}

bool Complex::operator==(const Complex& complex)
{
 return (_real == complex._real) && (_imag == complex._imag);
}

bool Complex::operator!=(const Complex& complex)
{
 return !(*this==complex);
}
 
Complex Complex::operator+(const Complex& complex)
{
 Complex c(*this);
 c._real +=complex._real;
 c._imag +=complex._imag;
 return c;
}
 
Complex& Complex::operator++()
{
 ++_real;
 return *this;
}
 
Complex Complex::operator++(int)
{
 Complex c;
 c._real=_real++;
 return c; 
}
 
Complex& Complex::operator+=(const Complex& complex)
{
 _real += complex._real;
 _imag += complex._imag;
 return *this;
}
 
Complex Complex::operator-(const Complex& complex)
{
 return Complex(_real - complex._real, _imag - complex._imag);
}
 
Complex& Complex::operator-=(const Complex& complex)
{
 _real -= complex._real;
 _imag -= complex._imag;
 return *this;
}
 
Complex& Complex::operator--()
{
 --_real;
 return *this;
}
 
Complex Complex::operator--(int)
{
 Complex c;
 c._real=_real--;
 return c;
}
 
Complex Complex::operator*(const Complex& complex)
{
 Complex c;
 c._real = _real*complex._real - _imag*complex._imag;
 c._imag = _real*complex._imag + _imag*complex._real;
 return c;
}
 
Complex& Complex::operator*=(const Complex& complex)
{
 float real = _real;
 _real = _real*complex._real - _imag*complex._imag;
 _imag = _imag*complex._real + real*complex._imag;
 return *this;
}
 
Complex Complex::operator/(const Complex& complex)
{
 return Complex((_real*complex._real + _imag*complex._imag) / 
                   (complex._real*complex._real + complex._imag*complex._imag),
       (_imag*complex._real - _real*complex._imag)/
       (complex._real*complex._real + complex._imag*complex._imag));
 /*Complex c;
 c._real = (_real*complex._real + _imag*complex._imag)*1.0 /
  (complex._real*complex._real + complex._imag*complex._imag);
 c._imag = (_imag*complex._real - _real*complex._imag)*1.0 /
  (complex._real*complex._real + complex._imag*complex._imag);
 return c;*/
}
 
Complex& Complex::operator/=(const Complex& complex)
{
 float real = _real;
 _real = (_real*complex._real + _imag*complex._imag)/
 (complex._real*complex._real + complex._imag*complex._imag);
 _imag = (_imag*complex._real - real*complex._imag) /
 (complex._real*complex._real + complex._imag*complex._imag);
 return *this;
}