#include <algorithm>
  void push_heap( iterator start, iterator end );
  void push_heap( iterator start, iterator end, StrictWeakOrdering cmp );

The push_heap() function adds an element (defined as the last element before end) to a heap (defined as the range of elements between [start,''end-1).

If the strict weak ordering comparison function object cmp is given, then it is used instead of the < operator to compare elements.

push_heap() runs in logarithmic time.