/in/foo.cc: In function 'int main()':
/in/foo.cc:28:24: error: invalid use of member function 'std::vector<_Tp, _Alloc>::size_type std::vector<_Tp, _Alloc>::size() const [with _Tp = int; _Alloc = std::allocator<int>; std::vector<_Tp, _Alloc>::size_type = long unsigned int]' (did you forget the '()' ?)
     for (i = 0; i < vc.size; i++)
                     ~~~^~~~