Eroare de compilare: user.cpp: In function ‘void remove_last(Deque*)’: user.cpp:43:6: error: reference to ‘is_empty’ is ambiguous if (is_empty(deque)) return; ^ user.cpp:26:6: note: candidates are: bool is_empty(Deque*) bool is_empty(Deque* deque) ^ In file included from /usr/include/c++/4.8/bits/move.h:57:0, from /usr/include/c++/4.8/bits/stl_pair.h:59, from /usr/include/c++/4.8/bits/stl_algobase.h:64, 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/istream:38, from /usr/include/c++/4.8/fstream:38, from user.cpp:1: /usr/include/c++/4.8/type_traits:536:12: note: template<class _Tp> struct std::is_empty struct is_empty ^ user.cpp: In function ‘void remove_first(Deque*)’: user.cpp:78:6: error: reference to ‘is_empty’ is ambiguous if (is_empty(deque)) return; ^ user.cpp:26:6: note: candidates are: bool is_empty(Deque*) bool is_empty(Deque* deque) ^ In file included from /usr/include/c++/4.8/bits/move.h:57:0, from /usr/include/c++/4.8/bits/stl_pair.h:59, from /usr/include/c++/4.8/bits/stl_algobase.h:64, 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/istream:38, from /usr/include/c++/4.8/fstream:38, from user.cpp:1: /usr/include/c++/4.8/type_traits:536:12: note: template<class _Tp> struct std::is_empty struct is_empty ^ user.cpp: In function ‘int main()’: user.cpp:104:11: error: reference to ‘is_empty’ is ambiguous while (!is_empty(deque) && A[get_last(deque)] >= A[i]) ^ user.cpp:26:6: note: candidates are: bool is_empty(Deque*) bool is_empty(Deque* deque) ^ In file included from /usr/include/c++/4.8/bits/move.h:57:0, from /usr/include/c++/4.8/bits/stl_pair.h:59, from /usr/include/c++/4.8/bits/stl_algobase.h:64, 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/istream:38, from /usr/include/c++/4.8/fstream:38,