Function pop_back

Fleece/Support/SmallVector.hh:132–132

        T& push_back(T&& t)                             {return * new(grow()) T(std::move(t));}

        void pop_back()                                 {get(_size - 1).~T(); --_size;}

        template <class... Args>
        T& emplace_back(Args&&... args) {