Eroare de compilare: user.cpp:26:8: error: specialization of ‘template<class _Tp> struct std::hash’ in different namespace [-fpermissive] struct hash<DSet> { ^ In file included from /usr/include/c++/4.8/bits/basic_string.h:3033:0, from /usr/include/c++/4.8/string:52, from /usr/include/c++/4.8/bits/locale_classes.h:40, from /usr/include/c++/4.8/bits/ios_base.h:41, from /usr/include/c++/4.8/ios:42, from /usr/include/c++/4.8/ostream:38, from /usr/include/c++/4.8/iostream:39, from user.cpp:1: /usr/include/c++/4.8/bits/functional_hash.h:58:12: error: from definition of ‘template<class _Tp> struct std::hash’ [-fpermissive] struct hash; ^