类的简单运算

#include <iostream>
using namespace std;
 
class rectangle
{
private:
    int length,width;
public:
    rectangle(){};
    rectangle(int a,int b);
    rectangle tlength(rectangle A,rectangle B);
    void display(rectangle C);
};
rectangle::rectangle(int a,int b)
{
    length=a;width=b;
}
rectangle rectangle::tlength(rectangle A,rectangle B)
{
    A.length= A.length + B.length;
    A.width=A.width+B.width;
    return A;
}
void rectangle::display(rectangle C)
{
    cout<<(C.length+C.width)*2;
}
void main()
{
    rectangle A(1,2),B(3,4),C;
    C=C.tlength(A,B);
    C.display(C);
}