Eroare de compilare: user.cpp: In function ‘bool cmp(Point, Point)’: user.cpp:39:18: error: reference to ‘ref’ is ambiguous return angle(ref, p) < angle(ref, q); ^ user.cpp:24:7: note: candidates are: Point ref Point ref; ^ In file included from /usr/include/c++/4.8/bits/stl_algo.h:66:0, from /usr/include/c++/4.8/algorithm:62, from user.cpp:3: /usr/include/c++/4.8/functional:493:5: note: template<class _Tp> std::reference_wrapper<_Tp> std::ref(std::reference_wrapper<_Tp>) ref(reference_wrapper<_Tp> __t) noexcept ^ /usr/include/c++/4.8/functional:485:10: note: template<class _Tp> void std::ref(const _Tp&&) void ref(const _Tp&&) = delete; ^ /usr/include/c++/4.8/functional:475:5: note: template<class _Tp> std::reference_wrapper<_Tp> std::ref(_Tp&) ref(_Tp& __t) noexcept ^ user.cpp:39:34: error: reference to ‘ref’ is ambiguous return angle(ref, p) < angle(ref, q); ^ user.cpp:24:7: note: candidates are: Point ref Point ref; ^ In file included from /usr/include/c++/4.8/bits/stl_algo.h:66:0, from /usr/include/c++/4.8/algorithm:62, from user.cpp:3: /usr/include/c++/4.8/functional:493:5: note: template<class _Tp> std::reference_wrapper<_Tp> std::ref(std::reference_wrapper<_Tp>) ref(reference_wrapper<_Tp> __t) noexcept ^ /usr/include/c++/4.8/functional:485:10: note: template<class _Tp> void std::ref(const _Tp&&) void ref(const _Tp&&) = delete; ^ /usr/include/c++/4.8/functional:475:5: note: template<class _Tp> std::reference_wrapper<_Tp> std::ref(_Tp&) ref(_Tp& __t) noexcept ^ user.cpp: In function ‘int main()’: user.cpp:61:5: error: reference to ‘ref’ is ambiguous ref = Point(INF, 0); ^ user.cpp:24:7: note: candidates are: Point ref Point ref; ^ In file included from /usr/include/c++/4.8/bits/stl_algo.h:66:0, from /usr/include/c++/4.8/algorithm:62, from user.cpp:3: /usr/include/c++/4.8/functional:493:5: note: template<class _Tp> std::reference_wrapper<_Tp> std::ref(std::reference_wrapper<_Tp>) ref(reference_wrapper<_Tp> __t) noexcept ^