include <map>
  include <iostream>
  using namespace std;
  
  class Data
  {
  public:
    Data(int val = 0) { mVal = val; }
    int getVal() const { return mVal; }
    void setVal(int val) {mVal = val; }
    // remainder of definition omitted 
  protected:
    int mVal;
  };
  
  int main(int argc, char** argv)
  {
    map<int, Data> dataMap;
    pair<map<int, Data>::iterator, bool> ret;
  
    ret = dataMap.insert(make_pair(1, Data(4)));
    if (ret.second) {
      cout << "Insert succeeded!\n";
    } else {
      cout << "Insert failed!\n";
    }
    
    ret = dataMap.insert(make_pair(1, Data(6)));
    if (ret.second) {
      cout << "Insert succeeded!\n";
    } else {
      cout << "Insert failed!\n";
    }
    return (0);
  }