class KeyObj
{
public:
string lastName;
string firstName;
bool operator< (const KeyObj &compare)
{
return lastName+firstName < compare.lastName+compare.firstName;
}
};
bool operator< (const KeyObj &source, const KeyObj &compare)
{
return source.lastName+source.firstName < compare.lastName+compare.firstName;
}
int main( int argc, char * argv[] )
{
map<KeyObj,string> myMap;
KeyObj k;
k.lastName="JONES";
k.firstName="BOB";
myMap[k] = "MR. BOB JONES";
KeyObj k2;
k2.lastName="JONES";
k2.firstName="FRED";
myMap[k2] = "MR. FRED JONES";
cout<<"Searching for FRED JONES:"<<endl;
KeyObj test;
test.lastName="JONES";
test.firstName="FRED";
if ( myMap.find(test) != myMap.end() )
{
cout<<myMap[test]<<endl;
}
else
cout<<"COULDN't FIND IT"<<endl;

#include <iostream>
#include <string>
#include <map>
 
class Person {
  std::string _first, _last;
public:
  Person(const std::string& first, const std::string& last)
    : _first(first), _last(last)
  {}
 
  bool operator<(const Person& p) const
  {
    //return _last < p._last;
    //return _first < p._first;
    return _last + _first < p._last + p._first;
  }
 
  friend std::ostream& operator<<(std::ostream& out, const Person& p)
  {
    return out<< p._last <<", "<< p._first;
  }
};
 
int main()
{
  std::map<Person, int> m;
 
  ++m[Person("John", "Doe")];
  ++m[Person("Jane", "Doe")];
  ++m[Person("", "Doe")];
  ++m[Person("John", "Doe")];
  ++m[Person("John", "")];
 
  std::map<Person, int>::iterator it = m.begin();
 
  while (it != m.end()) {
    std::cout<< it->first <<" -- "<< it->second <<std::endl;
    ++it;
  }
}