----- Mensaje original ----- De: Péter Szilágyi <peterke@gmail.com> Fecha: Martes, Mayo 22, 2007 9:39 pm Asunto: Re: [boost] Unordered Map/Set in VC++/Boost? Para: boost@lists.boost.org [...]
I don't really want to add additional libraries, that aren't needed. I'd rather solve it with the already available tools.
Boost.MultiIndex provides hashed indices, so you can emulate an unordered_set with a single-index multi_index_container. For instance, a TR1-compatible unordered set of ints would be defined as: #include <boost/multi_index_container.hpp> #include <boost/multi_index/hashed_index.hpp> #include <boost/multi_index/identity.hpp> typedef boost::multi_index_container< int, boost::multi_index::indexed_by< boost::multi_index::hashed_unique< boost::multi_index::identity<int> > >
int_unordered_set;
An emulation of an unordered map is a little more tricky and the result won't be TR1-compatible, but might be close enough for your needs, take for instance an unordered_map of ints to std::strings: #include <boost/multi_index_container.hpp> #include <boost/multi_index/hashed_index.hpp> #include <boost/multi_index/member.hpp> struct istr_pair { istr_pair(int i,const std::string& str): first(i),second(str){} int first; mutable std::string second; }; typedef boost::multi_index_container< istr_pair, boost::multi_index::indexed_by< boost::multi_index::hashed_unique< boost::multi_index::member< istr_pair,int,&istr_pair::first > > >
istr_unordered_map;
(Note that the second member of istr_pair is mutable so that we can freely modify it in elements of istr_unordered_map, which are treated as const, that's why we can use std::pair instead.) Best, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo