C++ priority queue custom comparator

Method1

#include <iostream>
#include <string>
#include <vector>
#include <queue>

using namespace std;

class Student{
public:
	Student(const string& name, int age):name(name), age(age){}

	friend bool operator<(const Student& lhs, const Student& rhs){
		if(lhs.name == lhs.name){
			return lhs.age < rhs.age;
		}
		return lhs.name < rhs.name;		
	}

	void output() const{
		cout<<"Name "<<name<<" Age "<<age<<endl;
	}

public:
	string name;
	int age;
};

int main(){
	priority_queue<Student> q;
	q.push(Student{"John", 21});
	q.push(Student{"John", 12});
	q.push(Student{"Ann", 24});

	while(!q.empty()){
		q.top().output();
		q.pop();
	}
	return 0;
}

Method2

#include <iostream>
#include <string>
#include <vector>
#include <queue>

using namespace std;

class Student{
public:
	Student(const string& name, int age):name(name), age(age){}

	bool operator<(const Student& other) const{
		if(name == other.name){
			return age < other.age;
		}
		return name < other.name;
	}

	void output() const{
		cout<<"Name "<<name<<" Age "<<age<<endl;
	}

public:
	string name;
	int age;
};

int main(){
	priority_queue<Student> q;
	q.push(Student{"John", 21});
	q.push(Student{"John", 12});
	q.push(Student{"Ann", 24});

	while(!q.empty()){
		q.top().output(); 
		q.pop();
	}
	return 0;
}

Method3

#include <iostream>
#include <string>
#include <vector>
#include <queue>

using namespace std;

class Student{
public:
	Student(const string& name, int age):name(name), age(age){}

	void output() const{
		cout<<"Name "<<name<<" Age "<<age<<endl;
	}

public:
	friend struct comp;

	string name;
	int age;
};

struct comp{
	bool operator()(const Student& lhs, const Student& rhs){
		if(lhs.name == lhs.name){
			return lhs.age < rhs.age;
		}
		return lhs.name < rhs.name;				
	}
};

int main(){
	priority_queue<Student, vector<Student>, comp> q;
	q.push(Student{"John", 21});
	q.push(Student{"John", 12});
	q.push(Student{"Ann", 24});

	while(!q.empty()){
		q.top().output(); 
		q.pop();
	}
	return 0;
}

Method4*

#include <iostream>
#include <string>
#include <vector>
#include <queue>

using namespace std;

class Student{
public:
	Student(const string& name, int age):name(name), age(age){}

	void output() const{
		cout<<"Name "<<name<<" Age "<<age<<endl;
	}

public:
	string name;
	int age;
};

bool comp(const Student& lhs, const Student& rhs){
	if(lhs.name == lhs.name){
		return lhs.age < rhs.age;
	}
	return lhs.name < rhs.name;				
}

int main(){
	priority_queue<Student, vector<Student>, std::function<bool(const Student&, const Student&)>> q(comp);
	q.push(Student{"John", 21});
	q.push(Student{"John", 12});
	q.push(Student{"Ann", 24});

	while(!q.empty()){
		q.top().output(); 
		q.pop();
	}
	return 0;
}

Method5

#include <iostream>
#include <string>
#include <vector>
#include <queue>

using namespace std;

class Student{
public:
	Student(const string& name, int age):name(name), age(age){}

	void output() const{
		cout<<"Name "<<name<<" Age "<<age<<endl;
	}

public:
	string name;
	int age;
};

int main(){

	auto comp = [](const Student& lhs, const Student& rhs)->bool{
		if(lhs.name == lhs.name){
			return lhs.age < rhs.age;
		}
		return lhs.name < rhs.name;	
	};

	priority_queue<Student, vector<Student>, decltype(comp)> q(comp);
	q.push(Student{"John", 21});
	q.push(Student{"John", 12});
	q.push(Student{"Ann", 24});

	while(!q.empty()){
		q.top().output(); 
		q.pop();
	}
	return 0;
}