given rna_sequencer_api.c gets included in a xxxx_gen.cc file, probably a good idea to rename that one to .cc as well

Looks incorrect that RNA_prototypes.h is a new file in this commit, since it's supposed to be generated automatically.

Do the casts in rna_sequencer.cc have to be C-style casts? I would think not, since they end up in a .cc file. It would be better to follow the style guide there then.

Given i took the initial stab at this, the macro's are there to use the codestyle preferred casts for C++. If we're settling for all c style casts, the macro's seemingly bring very little to the party, (maybe code readability is a little better? but it be by a hair at best for me personally) and we could just cast directly at the call site.

check to hear back from campbell's thoughts on this before making any changes though.

If we do keep the macro's they can be identical for C and C++ no need to differentiate anymore with c style casts.

I am fine with C-style casts too.

As for warnings, I have looked into solutions and so far don't quite understand this completely. I get, that function without declaration should be static, but if I define these as such, it does not compile. I think that git ignores _gen files so these may be declared somewhere, will look further into that. I also may generate some noise here, so I can check things on buildbot.

After bit of reverse engineering, I have found a solution (diff for one case):

diff --git a/source/blender/makesrna/intern/makesrna.c b/source/blender/makesrna/intern/makesrna.c
index 75b4d11bfbe..47ed53749ce 100644
--- a/source/blender/makesrna/intern/makesrna.c
+++ b/source/blender/makesrna/intern/makesrna.c
@@ -1505,7 +1505,8 @@ static char *rna_def_property_begin_func(

   func = rna_alloc_function_name(srna->identifier, rna_safe_id(prop->identifier), "begin");

-  fprintf(f, "void %s(CollectionPropertyIterator *iter, PointerRNA *ptr)\n", func);
+  const char *is_static = ((prop->flag_internal & PROP_INTERN_BUILTIN) != 0) ? "static" : "";
+  fprintf(f, "%s void %s(CollectionPropertyIterator *iter, PointerRNA *ptr)\n", is_static, func);
   fprintf(f, "{\n");

   if (!manualfunc) {

Not sure if this is best way to resolve this issue, but should be functionally same as previous C code. Also there may be more untreated warnings, will check that tomorrow.

Update: Unfortunately, above approach does not work for all functions. Will check few things, but I think I will need to seek advice.

I updated this patch to master and spent a bit trying to solve the warnings about static. I didn't find anything better than the diff above though yet. Here's the current patch: