C++ multiset upper_bound()

#include <iostream>
#include <set>
#include <string>
using namespace std;
class person/* ww w  .  j  a  v  a  2  s  .c o m*/
{
   private:
   string lastName;
   string firstName;
   long phoneNumber;
   public:                    // default constructor
   person() : lastName("blank"),
   firstName("blank"), phoneNumber(0)
   {  }
   // 3-arg constructor
   person(string lana, string fina, long pho) :
   lastName(lana), firstName(fina), phoneNumber(pho)
   {  }
   friend bool operator<(const person&, const person&);
   friend bool operator==(const person&, const person&);
   void display() const   // display person's data
   {
      cout << endl << lastName << ",\t" << firstName
      << "\t\tPhone: " << phoneNumber;
   }
};
// operator < for person class
bool operator<(const person& p1, const person& p2)
{
   if(p1.lastName == p2.lastName)
      return (p1.firstName < p2.firstName) ? true : false;
   return (p1.lastName < p2.lastName) ? true : false;
}
// operator == for person class
bool operator==(const person& p1, const person& p2)
{
   return (p1.lastName == p2.lastName &&
   p1.firstName == p2.firstName ) ? true : false;
}
int main()
{
   person pers1("D", "W", 8);
   person pers2("M", "S", 3);
   person pers3("B", "P", 6);
   person pers4("K", "B", 4);
   person pers5("W", "J", 9);
   person pers6("M", "A", 8);
   person pers7("F", "R", 7);
   person pers8("M", "S", 2);
   multiset< person, less<person> > persSet;
   // iterator to a multiset of persons
   multiset<person, less<person> >::iterator iter;
   persSet.insert(pers1);    // put persons in multiset
   persSet.insert(pers2);
   persSet.insert(pers3);
   persSet.insert(pers4);
   persSet.insert(pers5);
   persSet.insert(pers6);
   persSet.insert(pers7);
   persSet.insert(pers8);
   cout << "\nNumber of entries = " << persSet.size();
   iter = persSet.begin();   // display contents of multiset
   while( iter != persSet.end() )
      (*iter++).display();
   // get last and first name
   string searchLastName, searchFirstName;
   cout << "\n\nEnter last name of person to search for: ";
   cin >> searchLastName;
   cout << "Enter first name: ";
   cin >> searchFirstName;
   // create person with this name
   person searchPerson(searchLastName, searchFirstName, 0);
   // get count of such persons
   int cntPersons = persSet.count(searchPerson);
   cout << "Number of persons with this name = " << cntPersons;
   // display all matches
   iter = persSet.lower_bound(searchPerson);
   while( iter != persSet.upper_bound(searchPerson) )
      (*iter++).display();
   cout << endl;
   return 0;
}