[Boost-users] [parameter] Parameter-Enabled Class Templates: combining keyword and deduction for the same parameter

The docs explain that a parameter can be named: typedef parameter::parameters< requiredtag::threading_policy ...

class_signature; ... class_,...>;

or else be deduced: typedef parameter::parameters< required< deducedtag::threading_policy, is_base_and_derived > ...

class_signature; ... class multithreaded: threading_policy_marker{...}; class_;

Now, is it possible to combine these two options into one, so that the the two syntaxes class_,...>; class_; are accepted? If so, how? Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo