Compile error = g++ person.cpp personTest.cpp
/tmp/cc5BXASf.o(.text+0x2d): In function `main':
: undefined reference to `operator>>(std::basic_istream<char, std::char_traits<char> >&, Person&)'
collect2: ld returned 1 exit status

#ifndef PERSON_H
#define PERSON_H
#include <string>
#include <iostream>

using namespace std;

class Person {
 public:
	 friend ostream& operator<<( ostream& os, const Person& aPerson );
	 friend istream& operator>>( istream& is, Person& aPerson );
	 
	 //constructors
	 Person( string firstName, string lastName, int age, int numComputers );
	 Person();
	 
	 // Accessors
	 string getFirst() const;
	 string getLast() const;
	 string getFull() const;
	 string getShort() const;
	 int getAge() const;
	 int getNumComputers() const;
	 void print() const;
 
	 // Mutators
	 void set( string firstName, string lastName, int age, int numComputers );
	 void setFirstName( string firstName );
	 void setLastName( string lastName );
	 void setAge( int age );
	 void setNumComputers( int numComputers );
 private:
	 string _firstName;
	 string _lastName;
	 int _age, _numComputers;
};

#endif

#include "person.h"
#include <iostream>
#include <string>

using namespace std;

ostream& operator<<( ostream& os, const Person& aPerson ) {
	os << aPerson.getFirst() << "/"
		<< aPerson.getLast() << "/"
		<< aPerson.getAge() << "/"
		<< aPerson.getNumComputers();
	
	return os;
}

istream& operator>>( istream is, Person& aPerson ) {
	cout << "Please enter first name: ";
	string firstName;
	is >> firstName;
	cout << "Please enter last name: ";
	string lastName;
	is >> lastName;
	cout << "Please enter age: ";
	int age;
	is >> age;
	cout << "Please enter number of computers: ";
	int numComputers;
	is >> numComputers;
	aPerson.set( firstName, lastName, age, numComputers );
	
	return is;
}
	
//constructors
Person::Person( string firstName, string lastName, int age, int numComputers ) {
	set( firstName, lastName, age, numComputers);
}
Person::Person() {
	_firstName = "default";
	_lastName = "default";
	_age = -1;
	_numComputers = -1;
}

// Accessors
string Person::getFirst() const {
	return _firstName;
}
string Person::getLast() const {
	return _lastName;
}
string Person::getFull() const {
	return _firstName + " " + _lastName;
}
string Person::getShort() const {
	string empty;
	return empty + _firstName.at(0) + ". " + _lastName;
}
int Person::getAge() const {
	return _age;
}
int Person::getNumComputers() const {
	return _numComputers;
}
void Person::print() const {
	cout << getFirst() << endl;
	cout << getLast() << endl;
	cout << getFull() << endl;
	cout << getShort() << endl;
	cout << getAge() << endl;
	cout << getNumComputers() << endl;
}

// Mutators
void Person::set( string firstName, string lastName, int age, int numComputers ) {
	setFirstName( firstName );
	setLastName( lastName );
	setAge( age );
	setNumComputers( numComputers );
}
void Person::setFirstName( string firstName ) {
	_firstName = firstName;
}
void Person::setLastName( string lastName ) {
	_lastName = lastName;
}
void Person::setAge( int age ) {
	_age = age;
}
void Person::setNumComputers( int numComputers ) {
	_numComputers = numComputers;
}

#include "person.h"
#include <iostream>
#include <string>

using namespace std;

int main() {

  Person test;
  
  cin >> test;
  cout << test << endl;
  
  return 0;
}