Can I partially specialize a template with a pattern like foo?

Question

If this is possible, one can index into a variadic template parameter pack without recursion. However, GCC is refusing to pick up my partial specialization here:

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Answer 1

The spec says at 14.8.2.5p9

If P has a form that contains or , then each argument Pi of the respective template argument list P is compared with the corresponding argument Ai of the corresponding template argument list of A. If the template argument list of P contains a pack expansion that is not the last template argument, the entire template argument list is a non-deduced context.

Your typelist unfortunately matches that pattern.