I have my struct:
struct S{ int a; }; And i have class:
class Other{ //some fields }; I need write functor:
struct Comparator { bool operator()(S& l, S& r) { //some code, considered l,r and any object of class Other } }; In operator () should be considered any object of class Other. How to transfer object into functor? I use functor for priority_queue. Object of class Other can't be statical field.
Another ways for this purpose?
Make Comparator store an object of type Other(or reference, shared_ptr or unique_ptr depending on the ownership and validity semantics), and pass this in through Comparator's constructor.
struct Comparator { Comparator(const Other& val) : mVal(val){} bool operator()(S& l, S& r) { //Comparison code here uses l, r and mVal } private: Other mVal; }; Create the priority_queue like this, assuming you want to use vector<T> as the underlying container:
Other otherToHelpCompare; Comparator myComparator{otherToHelpCompare}; std::priority_queue<T, std::vector<T>, Comparator> q{myComparator}; 