Custom Sorting a vector of tuples

Question

I have a vector of tuples like

vector> v;

I believe that when the default comparison kicks in for tuple types, i

Answer 1

So here is the simplest way I learned how to do it (and I think it is even more straightforward than the main answer). This will work on any type in the tuple that can be compared with <.

Here is the sort function TupleLess, which takes advantage of some C style syntax:

 #include 
 #include 
 #include       

 template struct TupleLess
 {
    template
    bool operator() (const Tuple& left, const Tuple& right) const
    {
        return std::get(left) < std::get(right);
    }
};

int main(){
    //Define a Person tuple:    
    using Person = std::tuple;

    //Create some Person tuples and add to a vector
    Person person1 = std::make_tuple("John", "Smith", "323 Fake Street");
    Person person2 = std::make_tuple("Sheila", "Henrod", "784 Unreal Avenue");
    Person person3 = std::make_tuple("Mitch", "LumpyLumps", "463 Falsified Lane");

    std::vector vPerson = std::vector();
    vPerson.push_back(person1);
    vPerson.push_back(person2);
    vPerson.push_back(person3);

    //Sort by index at position 2
    std::sort(vPerson.begin(), vPerson.end(), TupleLess<2>());
}