#include <memory>
#include <boost/intrusive/unordered_set.hpp>

namespace bi=boost::intrusive;

class Item : public bi::unordered_set_base_hook<bi::link_mode<bi::safe_link>>
{

public:
	struct hash
	{
		size_t operator()(const Item &s) const
		{
			return /* ... */ 0;
		}
	};
};

void main()
{
	typedef bi::unordered_set<
		Item,
		bi::constant_time_size<false>,
		bi::hash<Item::hash>
	> map_type;

	std::unique_ptr<map_type::bucket_type[]> buckets;
	std::unique_ptr<map_type> set;
	buckets.reset(new map_type::bucket_type[50]);
	set.reset(new map_type(map_type::bucket_traits(buckets.get(),50)));

	// ... use the set

	set->clear_and_dispose([](Item *ptr) { delete ptr; });
}