PSS — PSS FTF issue: Restrictions on PSDL concrete types

A number of restrictions on concrete PSDL types have the effect
to force PSS users to use abstract types. For example keys can
only be defined on abstract storage homes, so in order to define
a key (and the implied finder operations), a PSS user needs
to define an abstract storage type and an abstract storage home.

Accessing storage objects and storage homes through abstract
storage types and homes provides flexibility (with some
PSS implementations this allows you to switch from one PSS
implementation to another one without recompiling or relinking
the code that uses the storage objects) but is also more complex
since it doubles the number of PSDL constructs you need.

For applications that don't need this flexibility, abstract
types are overkill – and make PSDL look quite complex to
understand and use. I propose to review the restrictions
on concrete types to make them usable without abstract types.

accepted