Boost.Flyweightのexampleにあるやつです。 #include <iostream> #include <boost/flyweight.hpp> #include <boost/flyweight/key_value.hpp> #include <boost/flyweight/no_tracking.hpp> #include <boost/noncopyable.hpp> using namespace boost::flyweights; struct compute_fibonacci; typedef flyweight</boost/noncopyable.hpp></boost/flyweight/no_tracking.hpp></boost/flyweight/key_value.hpp></boost/flyweight.hpp></iostream>