pre-typedef'ing a variadic-function-pointer argument

I have a function (foo) that takes a variadic function pointer as its argument. I would like to use "using" to define the argument's type prior to the function declaration.

template <typename ... vARGS> using TFuncType = void(*)(vARGS ... V_args);

template <typename ... vARGS> void foo(TFuncType<vARGS ...> funcptr) {}

void bar(int i) {}

int main()
  {
    foo(&bar); // This line fails to compile.
  }

This doesn't compile. The error (via clang using c++1z) is:

/make/proj/test/variadic-funcparam-deduce2.cpp:39:5: error: no matching function for call to 'foo'
foo(&bar);
^~~
/make/proj/test/variadic-funcparam-deduce2.cpp:33:36: note: candidate template ignored: substitution failure [with vARGS = int]
template <typename ... vARGS> void foo(TFuncType<vARGS ...> funcptr) {}

Why is the "int" substitution failing?

I can successfully compile if I explicitly write the type inside foo():

template <typename ... vARGS> void foo(void(*funcptr)(vARGS ... V_args)) {}

But I cannot get the initial ("using") version to work even when explicitly specifying the template parameters, and using a pre-casted TFuncType< int> for the argument, ie:

int main()
  {
    TF_call<int> fptr = &bar; // This line is OK.
    foo<int>(fptr);
  }

Does anyone know what's up here? Is there something strange about using typedef'd ("using") variadics and/or function pointers that I'm missing?