+namespace __gnu_cxx {
+
+ template< typename CharT, typename Traits, typename Alloc >
+ struct hash< std::basic_string<CharT, Traits, Alloc> > {
+ size_t operator()(const std::basic_string<CharT, Traits, Alloc>& s) const {
+
+ const std::collate<CharT>& c = std::use_facet< std::collate<CharT> >(std::locale());
+
+ return c.hash(s.c_str(), s.c_str() + s.size());
+
+ }
+
+ };
+
+ template< typename CharT, typename Traits, typename Alloc >
+ struct hash< const std::basic_string<CharT, Traits, Alloc> > { //yes you need this version aswell!
+
+ size_t operator()(const std::basic_string<CharT, Traits, Alloc>& s) const {
+
+ const std::collate<CharT>& c = std::use_facet< std::collate<CharT> >(std::locale());
+
+ return c.hash(s.c_str(), s.c_str() + s.size());
+ }
+
+ };
+};