how to generate sub-arrays from an array?

std::vector<int> v = {1, 2, 3, 4}; 
std::vector<std::vector<int>> subV;
for (int i = 0; i < v.size(); ++i) {
  for (int j = i + 1; j < v.size(); ++j) {
    subV.push_back(std::vector<int>(v.begin() + i, v.begin() + j));
  }
}