...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::container::pmr::flat_multimap_of
// In header: <boost/container/pmr/flat_map.hpp> template<typename Key, typename T, typename Compare = std::less<Key> > struct flat_multimap_of { // types typedef boost::container::flat_multimap< Key, T, Compare, polymorphic_allocator< std::pair< Key, T > > > type; };