I've attached to this email the first draft of my paper entitled
'interfaces', following on from my original post earlier today
entitled "Allow downcasting at compile time if Derived has no extra
member objects".

Also you can download the latest draft from here:

      http://www.virjacode.com/download/interface_latest_draft.pdf

Here's an excerpt of the syntax:

      interface lockable_bisem : std::binary_semaphore
      {
          void lock(void) noexcept(false) { acquire(); }
          void unlock(void) noexcept(false) { release(); }
      };