ATL / WTL / STL

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

class cat
{
public:
	cat(int age)
		: age_(age)
	{
	}

	int get_age() const { return age_; }

private:
	int age_;
};

bool apredicate(const cat& a, const cat& b)
{
return a.get_age() < b.get_age();
}

int main()
{
	vector<cat> v;
	v.push_back(cat(0));
	v.push_back(cat(2));
	v.push_back(cat(1));
	v.push_back(cat(4));
	v.push_back(cat(3));
	v.push_back(cat(9));
	sort(v.begin(),v.end(),apredicate);
	for(int i = 0; i < v.size(); i++)
	{
		cout << v.at(i).get_age() << endl;
	}
	return 0;
}