运算符重载

#include  <iostream>
#include  <cstdio>
#include  <algorithm>
using namespace std;

//+;-;*;
//int + obj
class A
{
  int a;
  int b;
  public :
  A(){a=0;b=0;}
  A(int a,int b)
  {
    this->a=a;
    this->b=b;
  }
  void setA(int x){a=x;}
  void setB(int x){b=x;}
  A operator+(const int x)
  {
    return A(a+x,b);
  }
  friend A operator+(const int x , A ax );
  friend ostream &operator<<(ostream &out,const A &Aa);
  friend istream &operator>>(istream &in,A &Aa);
  A operator()(int x,int y,int z)__________()
  {
    A ax;
    ax.a=x+y;
    ax.b=y+z;
    return ax;
    /*
    this->a=x+y;
    this->b=y+z;
    return *this;
    */
  }
  A operator+(const A&Aa)
  {
    A aa;
    aa.a=this->a+Aa.a;
    aa.b=this->b+Aa.b;
    return aa;
  }
  A operator*(const A&Aa)
  {
    A aa;
    aa.a=this->a*Aa.a;
    aa.b=this->b*Aa.b;
    return aa;
  }
  A operator-(const A&Aa)
  {
    A aa;
    aa.a=this->a-Aa.a;
    aa.b=this->b-Aa.b;
    return aa;
  }
  A operator-()
  {
    a=-a;
    b=-b;
    return A(a,b);
  }
  //qianzhui
A operator++()
{
  a+=1;
  b+=1;
  return *this;
}
//houzhui
A operator++(int)
{
  A aa(a,b);
  a++;
  b++;
  return aa;
}
ostream &operator<<(ostream &os)
{
  os<<this->a<<" "<<this->b;
  return os;
}
istream &operator>>(istream &is)
{
  is>>this->a>>this->b;
  return is;
}

  int getans()
  {
      return a*b;
  }
  int geta()
  {
    return a;
  }
  int getb()
  {
    return b;
  }
};

istream &operator>>(istream &in,A &Aa)
{
  in>>Aa.a>>Aa.b;
  return in;
}
ostream &operator<<(ostream &out,const A &Aa)
{
  out<<Aa.a<<" "<<Aa.b;
  return out;
}
A operator+(const int x ,A ax )
{
  return ax+x;
}

int main()
{
  A a;
  A b;
  A c;
  a.setA(71);
  a.setB(61);
  b.setA(11);
  b.setB(61);
  a=b-a;
  a=a+100;
  a=100+a;
  a=a.operator+(b);
  c=a(1,2,3);
  //a<<cout<<endl;
  cout<<c<<endl;
  //a>>cin;
  //cin>>a;

  //cout<<a.getb()<<endl<<a.geta()<<endl;
//cout<<c.getans()<<endl;
}