#include <vector>
#include <cassert>

struct Card {
  Card(int) {}
};

template<class F>
void repeat(unsigned times, F callback) {
  while (times--) callback();
}

int main() {
  std::vector<Card> cards;
  for (int i = 0; i < 42; i++) {
    repeat(10, [&] { cards.push_back(Card(i)); });
  }
  assert(cards.size() == 420);
}