In c++17 `template <auto>` allows to declare templates with arbitrary type parameters. Partially inspired by [this](https://stackoverflow.com/q/51056414/8769985) question, it would be useful to have an extension of `template <auto>` that captures both type and nontype template parameters, and also allows for a variadic version of it.

Are there plans for such an extension in the next c++20 release? Is there some fundamental problem in having a syntax like `template<auto... X>`, with `X` any type or nontype template parameter?