For 3.0.0 (T793)... For pcmk_cluster_t, we can replace all deprecated struct members except destroy() and cpg with a void *private member that can be used internally for a new internal struct containing the deprecated members.

In T788#12087, @kgaillot wrote:

Ah right, whenever we did this before, we used new value names as well. Let's define new names like pcmk_cluster_type_corosync. (Or maybe pcmk_cluster_layer/pcmk_cluster_layer_corosync.)

From crm/cluster.h, sbd uses send_cluster_text() and crm_msg_ais but only if HAVE_DECL_PCMK_CLUSTER_CLASSIC_AIS

From the GitHub discussion:

deprecate (via doxygen comments)

On that note, considering that Corosync has been the only supported cluster type for a long time now, I wonder to what extent this stuff even needs to be public. We can always add public API functions again after branching to 3.0.0. Might even make some naming issues easier in the interim, if we can work with things internally without introducing new public names yet.

enum cluster_type_e: deprecate this name and create an equivalent enum pcmk_cluster_type (the enum value names are fine and do not need to be deprecated)

One of the next things on my agenda is to do mass, quick-and-dirty deprecations -- pcmk__*() with public wrapper, no best practices or refactors otherwise, to ensure we get as much deprecated as possible in time.