/in/foo.cc:33:1: error: 'BFS' does not name a type
 BFS:
 ^~~
In file included from /usr/include/c++/6/deque:63:0,
                 from /usr/include/c++/6/queue:60,
                 from /in/foo.cc:36:
/usr/include/c++/6/bits/stl_uninitialized.h: In static member function 'static _ForwardIterator std::__uninitialized_copy<_TrivialValueTypes>::__uninit_copy(_InputIterator, _InputIterator, _ForwardIterator)':
/usr/include/c++/6/bits/stl_uninitialized.h:75:3: error: '_Construct' is not a member of 'std'
   std::_Construct(std::__addressof(*__cur), *__first);
   ^~~
/usr/include/c++/6/bits/stl_uninitialized.h:80:8: error: '_Destroy' is not a member of 'std'
        std::_Destroy(__result, __cur);
        ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In static member function 'static void std::__uninitialized_fill<_TrivialValueType>::__uninit_fill(_ForwardIterator, _ForwardIterator, const _Tp&)':
/usr/include/c++/6/bits/stl_uninitialized.h:142:3: error: '_Construct' is not a member of 'std'
   std::_Construct(std::__addressof(*__cur), __x);
   ^~~
/usr/include/c++/6/bits/stl_uninitialized.h:146:8: error: '_Destroy' is not a member of 'std'
        std::_Destroy(__first, __cur);
        ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In static member function 'static _ForwardIterator std::__uninitialized_fill_n<_TrivialValueType>::__uninit_fill_n(_ForwardIterator, _Size, const _Tp&)':
/usr/include/c++/6/bits/stl_uninitialized.h:202:3: error: '_Construct' is not a member of 'std'
   std::_Construct(std::__addressof(*__cur), __x);
   ^~~
/usr/include/c++/6/bits/stl_uninitialized.h:207:8: error: '_Destroy' is not a member of 'std'
        std::_Destroy(__first, __cur);
        ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function '_ForwardIterator std::__uninitialized_copy_a(_InputIterator, _InputIterator, _ForwardIterator, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:272:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__result, __cur, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function 'void std::__uninitialized_fill_a(_ForwardIterator, _ForwardIterator, const _Tp&, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:321:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__first, __cur, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function '_ForwardIterator std::__uninitialized_fill_n_a(_ForwardIterator, _Size, const _Tp&, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:348:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__first, __cur, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function '_ForwardIterator std::__uninitialized_copy_move(_InputIterator1, _InputIterator1, _InputIterator2, _InputIterator2, _ForwardIterator, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:389:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__result, __mid, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function '_ForwardIterator std::__uninitialized_move_copy(_InputIterator1, _InputIterator1, _InputIterator2, _InputIterator2, _ForwardIterator, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:417:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__result, __mid, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function '_ForwardIterator std::__uninitialized_fill_move(_ForwardIterator, _ForwardIterator, const _Tp&, _InputIterator, _InputIterator, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:439:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__result, __mid, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function 'void std::__uninitialized_move_fill(_InputIterator, _InputIterator, _ForwardIterator, _ForwardIterator, const _Tp&, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:464:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__first2, __mid2, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In static member function 'static void std::__uninitialized_default_1<_TrivialValueType>::__uninit_default(_ForwardIterator, _ForwardIterator)':
/usr/include/c++/6/bits/stl_uninitialized.h:484:3: error: '_Construct' is not a member of 'std'
   std::_Construct(std::__addressof(*__cur));
   ^~~
/usr/include/c++/6/bits/stl_uninitialized.h:488:8: error: '_Destroy' is not a member of 'std'
        std::_Destroy(__first, __cur);
        ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In static member function 'static _ForwardIterator std::__uninitialized_default_n_1<_TrivialValueType>::__uninit_default_n(_ForwardIterator, _Size)':
/usr/include/c++/6/bits/stl_uninitialized.h:519:3: error: '_Construct' is not a member of 'std'
   std::_Construct(std::__addressof(*__cur));
   ^~~
/usr/include/c++/6/bits/stl_uninitialized.h:524:8: error: '_Destroy' is not a member of 'std'
        std::_Destroy(__first, __cur);
        ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function 'void std::__uninitialized_default_a(_ForwardIterator, _ForwardIterator, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:597:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__first, __cur, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function '_ForwardIterator std::__uninitialized_default_n_a(_ForwardIterator, _Size, _Allocator&)':
/usr/include/c++/6/bits/stl_uninitialized.h:628:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__first, __cur, __alloc);
    ^~~
/usr/include/c++/6/bits/stl_uninitialized.h: In function '_ForwardIterator std::__uninitialized_copy_n(_InputIterator, _Size, _ForwardIterator, std::input_iterator_tag)':
/usr/include/c++/6/bits/stl_uninitialized.h:650:6: error: '_Construct' is not a member of 'std'
      std::_Construct(std::__addressof(*__cur), *__first);
      ^~~
/usr/include/c++/6/bits/stl_uninitialized.h:655:4: error: '_Destroy' is not a member of 'std'
    std::_Destroy(__result, __cur);
    ^~~
In file included from /usr/include/c++/6/deque:66:0,
                 from /usr/include/c++/6/queue:60,
                 from /in/foo.cc:36:
/usr/include/c++/6/bits/deque.tcc: In member function 'void std::deque<_Tp, _Alloc>::_M_default_initialize()':
/usr/include/c++/6/bits/deque.tcc:83:11: error: '_Destroy' is not a member of 'std'
           std::_Destroy(this->_M_impl._M_start, iterator(*__cur, __cur),
           ^~~
/usr/include/c++/6/bits/deque.tcc: In member function 'void std::deque<_Tp, _Alloc>::_M_fill_initialize(const value_type&)':
/usr/include/c++/6/bits/deque.tcc:391:11: error: '_Destroy' is not a member of 'std'
           std::_Destroy(this->_M_impl._M_start, iterator(*__cur, __cur),
           ^~~
/usr/include/c++/6/bits/deque.tcc: In member function 'void std::deque<_Tp, _Alloc>::_M_range_initialize(_ForwardIterator, _ForwardIterator, std::forward_iterator_tag)':
/usr/include/c++/6/bits/deque.tcc:450:13: error: '_Destroy' is not a member of 'std'
             std::_Destroy(this->_M_impl._M_start,
             ^~~
/usr/include/c++/6/bits/deque.tcc: In member function 'void std::deque<_Tp, _Alloc>::_M_destroy_data_aux(std::deque<_Tp, _Alloc>::iterator, std::deque<_Tp, _Alloc>::iterator)':
/usr/include/c++/6/bits/deque.tcc:834:3: error: '_Destroy' is not a member of 'std'
   std::_Destroy(*__node, *__node + _S_buffer_size(),
   ^~~
/usr/include/c++/6/bits/deque.tcc:839:5: error: '_Destroy' is not a member of 'std'
     std::_Destroy(__first._M_cur, __first._M_last,
     ^~~
/usr/include/c++/6/bits/deque.tcc:841:5: error: '_Destroy' is not a member of 'std'
     std::_Destroy(__last._M_first, __last._M_cur,
     ^~~
/usr/include/c++/6/bits/deque.tcc:845:3: error: '_Destroy' is not a member of 'std'
   std::_Destroy(__first._M_cur, __last._M_cur,
   ^~~
In file included from /usr/include/c++/6/vector:64:0,
                 from /usr/include/c++/6/queue:61,
                 from /in/foo.cc:36:
/usr/include/c++/6/bits/stl_vector.h: In destructor 'std::vector<_Tp, _Alloc>::~vector()':
/usr/include/c++/6/bits/stl_vector.h:426:9: error: '_Destroy' is not a member of 'std'
       { std::_Destroy(thi