-----Original Message----- From: boost-bounces@lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Arkadiy Vertleyb
REPEAT ENUM SEQ_ENUM SEQ_FOR_EACH_I SEQ_FOLD_LEFT
Which one is failing?
I know that REPEAT is working and SEQ_FOR_EACH_I is failing -- if you want me I can try the rest.
As you alluded to, SEQ_FOR_EACH_I is not auto-recursive, and thus can't be used inside itself. In order to make it as generally useful as possible, you can respecify you're macro so it only uses auto-recursive constructs. To give you an idea of why it isn't designed to work... SEQ_FOR_EACH_I is implemented in terms of FOR. SEQ_FOR_EACH_I passes to FOR a predicate (which determines if the sequence is "nil"), an operation (which increments 'i' and pops the head of the sequence), and a target macro (which calls the user-defined macro passed to SEQ_FOR_EACH_I). In order to make the above work, you'd need to replicate SEQ_FOR_EACH_I and the target macro passed to FOR however many times you want it to be reentrant. Of course, for consistency, you'd need to do that for all of the other higher-order algorithms that are built on top of other higher-order algorithms in the library--which is a lot of replication. I consider this a huge extensibility failure of the pp-lib (and have for several years now).
Happy New Year!
To you as well. Regards, Paul Mensonides