关于C++运算符重载的问题
最近学习C++ 的运算符重载，看课本上的代码写了后输出显示和课本上的不一样，而且值很奇怪 
#C/C++#
#include <iostream>
using namespace std;
//using std::cout;
//using std::endl;
class Complex{
public:
double real;
double image;
public:
Complex(double real = 0, double image = 0){
this->real = real;
this->image = image;
}
void display(){
cout << "(" << real << "," << image << ")" << endl;
}
friend Complex operator + (Complex A, Complex B); //重载 +
friend Complex operator - (Complex A, Complex B); //重载 -
friend Complex operator - (Complex A); //重载取负
friend Complex operator ++ (Complex &A); //重载前置自增
friend Complex operator ++ (Complex &A, int); //重载后置自增
};
Complex operator + (Complex A, Complex B){
return (A.real + B.real, A.image + B.image);
}
Complex operator - (Complex A, Complex B){
return (A.real - B.real, A.image - B.image);
}
Complex operator - (Complex A){
return (-A.real, -A.image);
}
Complex operator ++ (Complex &A){
cout << "pre" << A.real << "," << A.image << endl;
return (++A.real, A.image);
}
Complex operator ++ (Complex &A, int){
cout << "post" << A.real << "," << A.image << endl;
return (A.real++, A.image);
}
int main(){
Complex A(100.0, 200.0), B(-10.0, 20.0), C;
cout << "A=", A.display();
cout << "B=", B.display();
C = ++A;
cout << "C = ++A", C.display();
cout << "A=", A.display();
C = A++;
cout << "C = A++"; C.display();
cout << "A=" ; A.display();
return 0;
} 这里很奇怪，C输出的real值变成了200， image值变成了0，
还有下面的警告，不知道该怎么解决
希望有大佬能帮我一下
#C/C++#