In file included from /usr/include/c++/5/iostream:39:0,
                 from meme.cpp:1:
/usr/include/c++/5/ostream: In function ‘int main()’:
/usr/include/c++/5/ostream:384:7: error: ‘std::basic_ostream<_CharT, _Traits>::basic_ostream() [with _CharT = char; _Traits = std::char_traits<char>]’ is protected
       basic_ostream()
       ^
meme.cpp:7:13: error: within this context
     ostream os;
             ^
In file included from /usr/include/c++/5/ios:42:0,
                 from /usr/include/c++/5/ostream:38,
                 from /usr/include/c++/5/iostream:39,
                 from meme.cpp:1:
/usr/include/c++/5/bits/ios_base.h: In member function ‘std::basic_ios<char>& std::basic_ios<char>::operator=(const std::basic_ios<char>&)’:
/usr/include/c++/5/bits/ios_base.h:858:5: error: ‘std::ios_base& std::ios_base::operator=(const std::ios_base&)’ is private
     operator=(const ios_base&);
     ^
In file included from /usr/include/c++/5/ios:44:0,
                 from /usr/include/c++/5/ostream:38,
                 from /usr/include/c++/5/iostream:39,
                 from meme.cpp:1:
/usr/include/c++/5/bits/basic_ios.h:67:11: error: within this context
     class basic_ios : public ios_base
           ^
In file included from /usr/include/c++/5/iostream:39:0,
                 from meme.cpp:1:
/usr/include/c++/5/ostream: In member function ‘std::basic_ostream<char>& std::basic_ostream<char>::operator=(const std::basic_ostream<char>&)’:
/usr/include/c++/5/ostream:58:11: note: synthesized method ‘std::basic_ios<char>& std::basic_ios<char>::operator=(const std::basic_ios<char>&)’ first required here
     class basic_ostream : virtual public basic_ios<_CharT, _Traits>
           ^
meme.cpp: In function ‘int main()’:
meme.cpp:8:8: note: synthesized method ‘std::basic_ostream<char>& std::basic_ostream<char>::operator=(const std::basic_ostream<char>&)’ first required here
     os = cout;
        ^