C++ std list sort with custom comparator that depends on an member variable for the object instance

Question

Class:

Class:
  private:
    ...
    vector words; 
    vector< list > vints;
  public:
    myFunction(...)

Answer 1

@Kerrek's answer involving lambdas is better. But, if you must avoid C++11 features, then replace your sort function with a functor. Allow that functor to store a reference to whatever data is required, as so:

#include <vector>
#include <list>
#include <string>

class myClass {
private:
  std::vector<std::string> words;
  std::vector<std::list<int> > vints;

  // Instead of sortFunc, use sortFunctor. A functor can be used in place 
  // of a function in many places, and it can carry state (like a reference
  // to the data it needs).
  struct sortFunctor {
    const std::vector<std::string>& words;
    sortFunctor(const std::vector<std::string>& words) : words(words) { }
    bool operator()(int i, int j) { return words[i] < words[j]; }
  };

public:
  void myFunction() {
    vints[0].sort(sortFunctor(words));
  }
  myClass() {
    words.push_back("apple");
    words.push_back("berry");
    std::list<int> l;
    l.push_back(0);
    l.push_back(1);
    vints.push_back(l);
  }
};

int main () {
  myClass object;
  object.myFunction();
}

Answer 2

With lambdas:

vints[i].sort([&words](int i, int j) { return words[i] < words[j]; });

With std::bind:

#include <functional>

//...
{
  using namespace std::placeholders;
  vints[i].sort(std::bind(&myClass::sortFunc, this, _1, _2));
}