namespace boost {
  namespace lockfree {
    template<bool IsFixedSized> struct fixed_sized;
    template<size_t Size> struct capacity;
    template<typename Alloc> struct allocator;
  }
}

namespace boost {
  namespace lockfree {
    template<typename T, typename... Options> class queue;
  }
}

namespace boost {
  namespace lockfree {
    template<typename T, typename A0, typename A1> class spsc_queue;
  }
}

namespace boost {
  namespace lockfree {
    template<typename T, typename A0, typename A1, typename A2> class stack;
  }
}