text: #include <iostream>
  #include <vector>
  #include <list>
  #include <algorithm>
  #include "print_compiler.hpp"
  
  using namespace std;
  
  struct no_seven {};
  struct one_seven {};
  
  int main (int argc, char* argv[]) 
  {
      print_compiler();
      vector<int> seq= {3, 4, 7, 9, 2, 5, 7, 8};
      auto it= find(seq.begin(), seq.end(), 7); // first 7
      if (it == seq.end()) 
  	throw no_seven{};
      auto end= find(it+1, seq.end(), 7); // second 7
      if (end == seq.end()) 
  	throw one_seven{};
      for (; it != end+1; ++it)
  	cout << *it << ' ';
      cout << '\n';
  
      return 0;
  }
  
  