PSS — PSS FTF: Read-only operations on storage objects

With some object oriented programming languages (C++, Ada95), it is
possible to specify a method as read-only or read-write.
For example in C++, a 'const' member function has read-only access
to the data members of the target object.

So far in IDL and PSDL, there is no way to mark an operation as
read-only – this makes sense for interfaces, since a CORBA object
exposes only operations, not state.
For stateful objects, such as PSDL storage objects and IDL values,
being able to specify an operation as read-only would be very
useful. For example in C++ a 'in storage object' parameter
could be mapped to a pointer to a const C++ object, which is exactly
the semantics of 'in'. More generally, writing const-correct program
in C++ (Ada etc.) with PSS would become possible.

accepted