I'm trying to use Boost-MultiIndex to achieve: 1) the equivalent (or similar) functionality & performance of an std::map<std::string, ValType> with searches by std::string 2) perform searches by const char* without creating a temporary std::string and without copying the actual char's --------------------------code----------------------- #include <string> #include <functional> #include <cassert> #include <boost/multi_index_container.hpp> #include <boost/multi_index/ordered_index.hpp> #include <boost/multi_index/member.hpp> using namespace boost; using namespace boost::multi_index; struct elem { std::string m_key; double m_value; elem( const std::string& key, double value) : m_key(key), m_value(value) {} }; struct less_string : std::less<std::string> { using std::less<std::string>::operator(); // use operator< bool operator() (const std::string& lhs, const char* rhs) const {return lhs < rhs;} bool operator() (const char* lhs, const std::string& rhs) const {return lhs < rhs;} }; typedef multi_index_container< elem, indexed_by< ordered_unique< member<elem,std::string,&elem::m_key>, less_string > >
elem_set;
int main() { elem_set s; s.insert( elem("p", 1.0) ); assert( s.find("p") != s.end() ); // no temporary and no data copy! I did it! return 0; } --------------------------code----------------------- Is this the right way to go? Any hint will be appreciated. TIA PS: I know I'm actually getting something more like a std::set, it's ok