On 7/18/2011 4:04 AM, TONGARI wrote:

2011/7/18 Edward Diener <eldiener@tropicsoft.com

<mailto:eldiener@tropicsoft.com>>

   On 7/17/2011 1:29 PM, Edward Diener wrote:

       On 7/17/2011 9:21 AM, TONGARI wrote:

           Hello,

           I'd like to have a macro like:

           BUILD_HIERARCHY
           (a,
           (b,)
           (c,
           (d,)
           (e,)
           )
           )

           which should expand to:

           struct a {};
           struct b: a {};
           struct c: a {};
           struct d: c {};
           struct e: c {};

           Is this possible at all?
           I have tried but with no luck, if this is impossible, please
           tell me so.


       I think you want above:

       (a,
       (b)
       (c,
       (d)
       (e)
       )
       )

       This is a tuple with a possible second element as a seq. Each
       element of
       your seq is a tuple with the same rule as the top tuple.

       Following internal logic, perhaps with nested BOOST_PP_WHILEs, you
       should be able to cycle through each tuple and nested tuple
       forming the
       relationships you have created for your structs above. I can not
       guarantee this will be doable but at least you should have some
       idea of
       what to do from the description of what you have.


   I have to correct the above. The syntax for what I described must be:

   (a,
      ((b))
      ((c,
         (d)
         (e))
      )

   )


I think I need the comma since I don't assume variadic macro.

I do not understand what you mean by that, and what some extra comma has to do with variadic macros

I still do not have the above right. It should be:

(a,
  ((b))
  ((c,
      ((d))
      ((e))
   )
  )

)

Just in case you do not know, you can use the Wave trace facility to see how your macros above are expanding when you invoke BUILD_HIERARCHY with your two parameters.