#include <vector>
#include <iostream>
using namespace std;

class _vector {
    vector<int> x = {1, 2, 3};
public:
    vector<int>::iterator begin(){
        return x.begin();
    }

    vector<int>::iterator end(){
        return x.end();
    }

    vector<int>::const_iterator cbegin() const {
        return x.cbegin();
    }

    vector<int>::iterator cend() const {
        return x.cend();
    }

    void test() const {
        for(const int& i : x)
            cout << i << " ";
    }

};

int main()
{
    _vector a;
    a.test();
}