c++运算符重载实例

#include <iostream>using namespace std;class complex {public:complex() : m_real(0.0), m_imag(0.0) { };complex(double a, double b) : m_real(a), m_imag(b) { };public:friend complex operator+(const complex & A, const complex & B);friend complex operator-(const complex & A, const complex & B);friend complex operator*(const complex & A, const complex & B);friend complex operator/(const complex & A, const complex & B);friend istream & operator >> (istream & in, complex & A);friend ostream & operator<<(ostream & out, complex & A);private:double m_real;  //实部double m_imag;  //虚部};//重载加法运算符complex operator+(const complex & A, const complex &B) {complex C;C.m_real = A.m_real + B.m_real;C.m_imag = A.m_imag + B.m_imag;return C;}//重载减法运算符complex operator-(const complex & A, const complex &B) {complex C;C.m_real = A.m_real - B.m_real;C.m_imag = A.m_imag - B.m_imag;return C;}//重载乘法运算符complex operator*(const complex & A, const complex &B) {complex C;C.m_real = A.m_real * B.m_real - A.m_imag * B.m_imag;C.m_imag = A.m_imag * B.m_real + A.m_real * B.m_imag;return C;}//重载除法运算符complex operator/(const complex & A, const complex & B) {complex C;double square = A.m_real * A.m_real + A.m_imag * A.m_imag;C.m_real = (A.m_real * B.m_real + A.m_imag * B.m_imag) / square;C.m_imag = (A.m_imag * B.m_real - A.m_real * B.m_imag) / square;return C;}//重载输入运算符istream & operator >> (istream & in, complex & A) {in >> A.m_real >> A.m_imag;return in;}//重载输出运算符ostream & operator<<(ostream & out, complex & A) {out << A.m_real << " + " << A.m_imag << " i ";;return out;}int main() {complex c1, c2, c3;cin >> c1 >> c2;c3 = c1 + c2;cout << "c1 + c2 = " << c3 << endl;c3 = c1 - c2;cout << "c1 - c2 = " << c3 << endl;c3 = c1 * c2;cout << "c1 * c2 = " << c3 << endl;c3 = c1 / c2;cout << "c1 / c2 = " << c3 << endl;system("pause");return 0;}