Created a boost::priority_queue with my comparison operation defined. Here is how my priority_queue looks, boost::heap::priority_queue<myObject*, boost::heap::compare<myObjectPtrCompare> > max_heap; My comparison is defined as, struct myObjectPtrCompare{ bool operator()(const myObject* lhs, const myObject* rhs) const { return (lhs->getTime() < rhs->getTime()); }}; I have used it as, myObject* obj1 = static_cast<myObject*>(base1); 'base1' is an object of class 'myBase'(base class of myObject) myObject and getTime() within it used for comparision are defined as, class myObject : public myBase { Time getTime() const { return time; }... ...} Compiling this gives me this error, c:\Projects\pq_test.cpp(27): error C2662: 'void boost::heap::priority_queue<myObject*,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_>::push(myObject *const &)' : cannot convert 'this' pointer from 'const boost::heap::priority_queue<myObject *,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_>' to 'boost::heap::priority_queue<myObject *,boost::heap::compare<myObjectPtrCompare>,boost::parameter::void_,boost::parameter::void_,boost::parameter::void_> &'1> Conversion loses qualifiers Using Visual Studio 2013 C++. I understand that I am doing something wrong with const correctness, but I am not able to figure out what is wrong. Any help is appreciated. TIA!