HELP! can't sort a STL list

Question

I declare a list like this:
               std::list<swedSim> usedSimList;
and a compare function to sort it:
     bool lt_fun_equip(const swedSim& s1, const swedSim& s2)
     return s1._maxAssEquipment - s1._assEquipmentCount - s1._assEquipmentRequestCount <
                    s2._maxAssEquipment - s2._assEquipmentCount - s2._assEquipmentRequestCount;
when I try to sort the list, this way:
                         usedSimList.sort(lt_fun_equip);
I get the following compile error:
"/opt/SUNWspro/WS6U2/include/CC/Cstd/./list.cc", line 351: Error: Too many arguments in call to "std::list<srh::swedSim, std::allocator<srh::swedSim>>::__adjacent_merge(std::list<srh::swedSim, std::allocator<srh::swedSim>>::iterator, std::list<srh::swedSim, std::allocator<srh::swedSim>>::iterator, std::list<srh::swedSim, std::allocator<srh::swedSim>>::iterator)".
"taskReqAssociation.cpp", line 268: Where: While instantiating "std::list<srh::swedSim, std::allocator<srh::swedSim>>::sort(bool(*)(const srh::swedSim&,const srh::swedSim&))".
"taskReqAssociation.cpp", line 268: Where: Instantiated from non-template code.
Any help would be highly appreciated!
Thank you in advance

Answer 1

     struct ltsim_equip : public binary_function<swedSim, swedSim, bool>
     bool operator()(const swedSim& s1, const swedSim& s2) const
          long diff;
          diff = s1._maxAssEquipment - s1._assEquipmentCount - s1._assEquipmentRequestCount -
                    s2._maxAssEquipment + s2._assEquipmentCount + s2._assEquipmentRequestCount;
     return (diff == 0 ? (s1._lastModDate < s2._lastModDate) : (diff > 0));
     bool lt_fun_acc(const swedSim& s1, const swedSim& s2)
          long diff;
          diff = s1._maxAssAccessory - s1._assAccessoryCount - s1._assAccessoryRequestCount -
                    s2._maxAssAccessory + s2._assAccessoryCount + s2._assAccessoryRequestCount;
     return (diff == 0 ? (s1._lastModDate < s2._lastModDate) : (diff > 0));
     void taskAssocReq::execute ()
          //define a list and an iterator
          std::list<swedSim> simList;
          std::list<swedSim>::iterator simIterator;
                         simList.clear();
// the following statement will initialize the list
                         lastProspectIsValid = getSimList(imeiItem->_prospectNum, simList, db);
                    if (imeiItem->isAccessory() && (simListSortedBy != ACCESSORIES)) {
                         simList.sort(lt_fun_acc); // THIS ONE WORKS
                         simListSortedBy = ACCESSORIES;
                    } else if (imeiItem->isEquipment() && (simListSortedBy != EQUIPMENTS)) {
                         simList.sort(ltsim_equip()); // THIS ONE DOES NOT!!!
                         simListSortedBy = EQUIPMENTS;