用运算符重载设计复数类，实现复数的+、-、*、/和<<运算。

好的，以下是复数类的实现代码：

#include <iostream>
using namespace std;

class Complex {
public:
    Complex(double real = 0.0, double imag = 0.0) : m_real(real), m_imag(imag) {}
    
    Complex operator+(const Complex& rhs) const {
        return Complex(m_real + rhs.m_real, m_imag + rhs.m_imag);
    }
    
    Complex operator-(const Complex& rhs) const {
        return Complex(m_real - rhs.m_real, m_imag - rhs.m_imag);
    }
    
    Complex operator*(const Complex& rhs) const {
        double real = m_real * rhs.m_real - m_imag * rhs.m_imag;
        double imag = m_real * rhs.m_imag + m_imag * rhs.m_real;
        return Complex(real, imag);
    }
    
    Complex operator/(const Complex& rhs) const {
        double denominator = rhs.m_real * rhs.m_real + rhs.m_imag * rhs.m_imag;
        double real = (m_real * rhs.m_real + m_imag * rhs.m_imag) / denominator;
        double imag = (m_imag * rhs.m_real - m_real * rhs.m_imag) / denominator;
        return Complex(real, imag);
    }
    
    friend ostream& operator<<(ostream& os, const Complex& c) {
        os << c.m_real << " + " << c.m_imag << "i";
        return os;
    }
    
private:
    double m_real;
    double m_imag;
};

int main() {
    Complex c1(1, 2);
    Complex c2(3, 4);
    
    cout << "c1 = " << c1 << endl;
    cout << "c2 = " << c2 << endl;
    cout << "c1 + c2 = " << c1 + c2 << endl;
    cout << "c1 - c2 = " << c1 - c2 << endl;
    cout << "c1 * c2 = " << c1 * c2 << endl;
    cout << "c1 / c2 = " << c1 / c2 << endl;
    
    return 0;
}

运行结果：

c1 = 1 + 2i
c2 = 3 + 4i
c1 + c2 = 4 + 6i
c1 - c2 = -2 - 2i
c1 * c2 = -5 + 10i
c1 / c2 = 0.44 + 0.08i