poeben

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

using namespace std;

template <typename T>
void print_results(T * first, T * last) {
    while (first != last) {
        cout << *first << ' ';
        first++;
    }
}

template <typename T>
void process(const vector<T>& data) {
    vector<T> result();
    typename vector<T>::iterator it;
    it = result.begin();
    T * filtered_last = copy_if(
        data.begin(),
        data.end(),
        it,
        [](const T& x) { return x > 0; }
    );

    print_results(filtered, filtered_last);
    delete result;
}

int main() {
    vector<int> r = { 1, 2, 3, -1, 5 };
    process(r);
}