Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Struct template stable

boost::heap::stable — Configure a heap as stable.

// In header: <boost/heap/policies.hpp>

template<bool T> 
struct stable {
};

A priority queue is stable, if elements with the same priority are popped from the heap, in the same order as they are inserted.