cppreference.com > C++ Algorithms > make_heap make_heap Syntax:
      #include <algorithm>
      void make_heap( iterator start, iterator end );
      void make_heap( iterator start, iterator end, StrictWeakOrdering cmp );
The make_heap() function turns the given range of elements [start,end) into a heap. If the strict weak ordering comparison function object cmp is given, then it is used instead of the < operator to compare elements. make_heap() runs in linear time. Related topics: is_heap pop_heap push_heap sort_heap