After n2369 we have a single push_back overload in the sequence containers, of the "emplace" type. At variance with that, still in n2461, we have two separate overloads, the C++03 one + one taking an rvalue reference in the container adaptors. Therefore, simply from a consistency point of view, I was wondering whether the container adaptors should be aligned with the specifications of the sequence container themselves: thus have a single push along the lines:

template<typename... _Args>
void
push(_Args&&... __args)
  { c.push_back(std::forward<_Args>(__args)...); }