Hello,
Let we have two variadic templates:
> template Qwerty(Values...) {}
> template Qaz(alias type, Data...) {}
Now I want to add a constraint to "Qwerty" so that each type in 
"Values" pack must be a "Qaz" template. I don't care about values 
of "type" or "Data" in "Qaz".
How to do it in D?