Add a note about Unpack

Author: msullivan

tests/test_fastapilike_1.py

@@ -72,6 +72,34 @@ class _Default:
     *[x for x in Iter[Members[T]]],
 ]
 
+"""TODO:
+
+We would really like to instead write:
+
+type AddInit[T] = NewProtocol[
+    InitFnType[T],
+    *Members[T]],
+]
+
+but we struggle here because typing wants to unpack the Members tuple
+itself.  I'm not sure if there is a nice way to resolve this. We
+*could* make our consumers (NewProtocol etc) be more flexible about
+these things but I don't think that is right.
+
+The frustrating thing is that it doesn't do much with the unpacked
+version, just some checks!
+
+We could fix typing to allow it, and probably provide a hack around it
+in the mean time.
+
+Lurr! Writing *this* gets past the typing checks (though we don't
+support it yet):
+
+type AddInit[T] = NewProtocol[
+    InitFnType[T],
+    *tuple[*Members[T]],
+]
+"""
 
 type AllOptional[T] = NewProtocol[
     *[