vector casting trickery

main.cpp

#include <array>
#include <iostream>
#include <vector>

int main() {
  std::vector<std::array<int, 2>> as{{1, 2}, {3, 4}, {7, -1}};
  int* buffer = (int*)as.data();

  for (int i = 0; i < as.size() * 2; i++) {
    std::cout << buffer[i] << std::endl;
  }

  return 0;
}