Variadic templates, parameter pack and its discussed ambiguity in a parameter list

Question

In this question, I\'ll refer to my previous question.

In that question, I found that the following is not valid:

template

        

Answer 1

In the class template, a prospective template argument list C<a,b,c,d,e,f> needs to match

template<typename T, typename... A, typename S>

in which ...A is just floating in a parameter list.

But in the specialization, what needs to be matched is not the list of template variabled but rather the pattern:

C<T(A...), S>

which is easy because the A... is delimited.

So in the template specialization, the list of parameters is just an inventory of symbols, some scalar and some parameter packs, which will appear in a pattern.