#include <iostream>
#include <vector>
using namespace std;
 
class hoge{
public:
  int *a;
  int size;
  hoge(int a[],int size):a(a),size(size){}
  hoge(hoge& h):a(h.a),size(h.size){}
  int sum(){
    int s=0;
    for(int i =0;i<size;i++)s+=a[i];
    return s;
  }
};
 
void push(hoge& h,vector<int>& vec,int value)
{
	vec.push_back(value);
	h = hoge(vec.data(),value);
}
 
int main(){
  vector<int> a={1,2,3};
  hoge huga(a.data(),a.size());
  cout<<huga.sum()<<endl;
  push(huga,a,4);
  cout<<huga.sum()<<endl;
  return 0;
}

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