#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

struct ha { 
	int i;
    explicit ha(int a) : i(a) {}
};

int main() 
{
    vector<ha> v{ ha{1}, ha{7}, ha{1} }; // initial vector
    // GOAL : make a vector of pointers to elements with i < 2
    vector<ha*> ph; // target vector
    vector<ha*> pv; // temporary vector
    // 1. 
    transform(v.begin(), v.end(), back_inserter(pv), 
        [](ha &arg) { return &arg; }); 
    // 2. 
    copy_if(pv.begin(), pv.end(), back_inserter(ph),
        [](ha *parg) { return parg->i < 2;  }); // 2. 

    return 0;
}