Variadic template aliases as template arguments
First some code, then some context, then the question:
template using id = T;
template class F, typename
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ISO C++11 14.3.3/1:
A template-argument for a template template-parameter shall be the name of a class template or an alias template, expressed as id-expression.
Plus I don't see any special exceptions for variadic template template parameters.
On the other hand, such template aliases cause serious problems in real-world code that I cannot reproduce here: frequent internal compiler errors for gcc, and less frequent unexpected behavior for clang (only in more advanced SFINAE tests).
Root of problems can be in other places. You should try to localize code which causes internal compiler error - just remove unrelated parts one by one (or use some kind of binary search, i.e. divide-and-conquer) - and check if error is still here on each stage.
As for GCC 4.9.0 error, try to change
template <typename... T> using map = F <T...>;to
template <typename... U> using map = F <U...>;Maybe this would help to understand what GCC sees.
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