Sort With Functors

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

template <typename T>
class ascOrder
{
public:
    bool operator()(const T& a, const T& b)
    {
        return (std::fabs(a) < std::fabs(b));
    }
};

template <typename T>
class revOrder
{
public:
    bool operator()(const T& a, const T& b)
    {
        return (std::fabs(a) > std::fabs(b));
    }
};

int main()
{
    std::vector<int> nums = {3, 4, 2, 5, 1}; // Pre-defined random order
 
    for(int i : nums)
    {
        std::cout << i << std::endl;
    }
 
    std::sort(nums.begin(), nums.end(), revOrder<int>());
    std::cout << "Reverse Order" << std::endl;
 
    for(int i : nums)
    {
        std::cout << i << std::endl;
    }
 
    return 0;
}

Just a little snippet showing how to use functors along with std::sort.