Crow：Middlewares 庖丁解牛4 partial_context

Crow：Middlewares 庖丁解牛3 pop_back-CSDN博客

已经分析了pop_pack，那么他是被用在什么地方呢？

template
struct partial_context : public black_magic::pop_back::template rebind, public black_magic::last_element_type::type::context
{
    using parent_context = typename black_magic::pop_back::template rebind<::crow::detail::partial_context>;
    template
    using partial = typename std::conditional>::type;

    template
    typename T::context& get()
    {
        return static_cast<