text: #include <iostream>
  #include <vector>
  
  void print(std::vector<int>& vec) {
    for (std::vector<int>::iterator iter = vec.begin(); iter != vec.end(); iter++) {
      std::cout << *iter << " ";
    }
    std::cout << std::endl;
  }
  
  int main(int argc, char* argv[]) {
    std::vector<int> vec;
    for (int i = 0; i < 10; i++) {
      vec.push_back(i + 1);
    }
    print(vec);
    
    int val;
    std::vector<int>::iterator iter = vec.begin();
    for (; iter != vec.end(); iter++) {
      if (*iter == 4) {
        val = *iter;
        vec.erase(iter);
        vec.insert(vec.begin() + 1, val);
        break;
      }
    }
    print(vec);
  }
  