Eroare de compilare: main.cpp:21:8: error: specialization of 'template<class _Tp> struct std::hash' in different namespace [-fpermissive] struct hash<Entry> { ^~~~~~~~~~~ In file included from /usr/include/c++/6/bits/basic_string.h:5646:0, from /usr/include/c++/6/string:52, from /usr/include/c++/6/bits/locale_classes.h:40, from /usr/include/c++/6/bits/ios_base.h:41, from /usr/include/c++/6/ios:42, from /usr/include/c++/6/istream:38, from /usr/include/c++/6/fstream:38, from main.cpp:1: /usr/include/c++/6/bits/functional_hash.h:58:12: error: from definition of 'template<class _Tp> struct std::hash' [-fpermissive] struct hash; ^~~~ Non zero exit status: 1