#include <algorithm>
#include <array>
#include <functional>
#include <iomanip>
#include <iostream>
 
void print(auto const& seq) {
    for (auto const& elem : seq)
        std::cout << elem << ' ';
    std::cout << '\n';
}
 
struct Particle {
    std::string name; double mass; // MeV
    friend std::ostream& operator<< (std::ostream& os, Particle const& p) {
        return os << "\n" << std::left << std::setw(8) << p.name << " : " << p.mass;
    }
};
 
int main()
{
    std::array s {5, 7, 4, 2, 8, 6, 1, 9, 0, 3};
 
    // sort using the default operator<
    std::ranges::stable_sort(s);
    print(s);
 
    // sort using a standard library compare function object
    std::ranges::stable_sort(s, std::ranges::greater());
    print(s);
 
    // sort using a custom function object
    struct {
        bool operator()(int a, int b) const {
            return a < b;
        }
    } customLess;
    std::ranges::stable_sort(s.begin(), s.end(), customLess);
    print(s);
 
    // sort using a lambda expression
    std::ranges::stable_sort(s, [](int a, int b) {
        return a > b;
    });
    print(s);
 
    // sort with projection
    Particle particles[] {
        {"Electron", 0.511}, {"Muon", 105.66}, {"Tau", 1776.86},
        {"Positron", 0.511}, {"Proton", 938.27}, {"Neutron", 939.57},
    };
    print(particles);
    std::ranges::stable_sort(particles, {}, &Particle::name); //< sort by name
    print(particles);
    std::ranges::stable_sort(particles, {}, &Particle::mass); //< sort by mass
    print(particles);
}