On Mon, Nov 5, 2018 at 12:01 AM Gavin Lambert via Boost-users
On 3/11/2018 11:34, Michael Powell wrote:
The forward declaration errors now the top most errors:
Fundamentally you have a cyclic recursion problem.
You're telling me. ;-)
You're trying to declare that ast_msg_body_t contains by value a variant which can contain a ast_group_t which can contain an ast_msg_body_t (and similarly for the other possible variant types).
There is no possible way this could compile, as this requires the type to be infinite size.
You will need to restructure things; in some cases you can rewrite things to use lists, although that's probably not appropriate here. In this case you probably need to introduce an indirection and kick something onto the heap rather than the stack.
For example, you could make the body members into unique_ptrs. This would also let you make the body type use inheritance-based polymorphism rather than using a variant (which one is better depends on taste and on intended usage).
Effectively, "rewriting" the AST in strategic places is what I did. I had some help, learned a couple of new tricks, and applications to a couple of old tricks, circa C++11 bits, at any rate, so far as I can determine. http://stackoverflow.com/questions/53120135/how-to-overcome-a-boost-spirit-a... And with several follow up posts.
(Also, while I'm not familiar with Spirit: there should be a way to make it output actual int values rather than strings, unless you need to preserve the input format.) _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org https://lists.boost.org/mailman/listinfo.cgi/boost-users