Eroare de compilare: user.cpp: In function ‘int main()’: user.cpp:32:6: error: no match for ‘operator<’ (operand types are ‘std::ofstream {aka std::basic_ofstream<char>}’ and ‘int’) g<nr; ^ user.cpp:32:6: note: candidates are: In file included from /usr/include/c++/4.8/bits/stl_algobase.h:64:0, from /usr/include/c++/4.8/bits/char_traits.h:39, from /usr/include/c++/4.8/ios:40, 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/stl_pair.h:220:5: note: template<class _T1, class _T2> constexpr bool std::operator<(const std::pair<_T1, _T2>&, const std::pair<_T1, _T2>&) operator<(const pair<_T1, _T2>& __x, const pair<_T1, _T2>& __y) ^ /usr/include/c++/4.8/bits/stl_pair.h:220:5: note: template argument deduction/substitution failed: user.cpp:32:7: note: ‘std::ofstream {aka std::basic_ofstream<char>}’ is not derived from ‘const std::pair<_T1, _T2>’ g<nr; ^ In file included from /usr/include/c++/4.8/bits/stl_algobase.h:67:0, from /usr/include/c++/4.8/bits/char_traits.h:39, from /usr/include/c++/4.8/ios:40, 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/stl_iterator.h:297:5: note: template<class _Iterator> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_Iterator>&) operator<(const reverse_iterator<_Iterator>& __x, ^ /usr/include/c++/4.8/bits/stl_iterator.h:297:5: note: template argument deduction/substitution failed: user.cpp:32:7: note: ‘std::ofstream {aka std::basic_ofstream<char>}’ is not derived from ‘const std::reverse_iterator<_Iterator>’ g<nr; ^ In file included from /usr/include/c++/4.8/bits/stl_algobase.h:67:0, from /usr/include/c++/4.8/bits/char_traits.h:39, from /usr/include/c++/4.8/ios:40, 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/stl_iterator.h:347:5: note: template<class _IteratorL, class _IteratorR> bool std::operator<(const std::reverse_iterator<_Iterator>&, const std::reverse_iterator<_IteratorR>&) operator<(const reverse_iterator<_IteratorL>& __x, ^ /usr/include/c++/4.8/bits/stl_iterator.h:347:5: note: template argument deduction/substitution failed: user.cpp:32:7: note: ‘std::ofstream {aka std::basic_ofstream<char>}’ is not derived from ‘const std::reverse_iterator<_Iterator>’ g<nr; ^ In file included from /usr/include/c++/4.8/bits/stl_algobase.h:67:0, from /usr/include/c++/4.8/bits/char_traits.h:39, from /usr/include/c++/4.8/ios:40, from /usr/include/c++/4.8/ostream:38, from /usr/include/c++/4.8/iostream:39, from user.cpp:1: