Custom comparator for set without overloading operator(), std::less, std::greater

I want a custom comparator for following code. However, I cannot overload operator(), std::less, std::greater. I tried to achieve this using lambdas but gcc won't allow me to use auto as non static member. Any other way to make this work?

#include <iostream>
#include <map>
#include <set>

class Test {
  public:

    // bool operator () (const int lhs, const int rhs) {
    //     return lhs > rhs;
    // };


    using list = std::multiset<int  /*, Test*/>;
    std::map<const char*, list> scripts;
};

int main() {
  Test t;

  t.scripts["Linux"].insert(5);
  t.scripts["Linux"].insert(8);
  t.scripts["Linux"].insert(0);

  for(auto a: t.scripts["Linux"]) {
    std::cout << a << std::endl;
  }

    std::cout << "end";
}