Re: [Boost-users] [Preprocessor] Is it possible to expand recursively?

17 Jul 2011

      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.

Re: [Boost-users] [Preprocessor] Is it possible to expand recursively?

Edward Diener