Please follow canonical C++ initialization:

FallbackProcessor(const FallbackProcessor &other) : transform(new FallbackTransform(*other.transform))
{
}

Or, since the change is so big anyway:

FallbackProcessor(const FallbackProcessor &other) : transform(make_unique<FallbackTransform>(*other.transform))
{
}
...
unique_ptr<FallbackTransform> transform;

Not related to the review, but it reads very weird "FooPtr *bar".
Did you figure out why is it so, and whether we can remove one level of indirection? You also mention C-API removal, so maybe there things are more clear?

Almost everywhere else in the file explicit comparison with NULL is used.

I'm not sure what you mean?

All OpenColorIO pointers are std::shared_ptr. If it's the RcPtr part of the name that is strange, we could drop that from the C API since it's not really adding information there. But I would prefer to do that as a cleanup after these changes.

Regarding C-API removal, what I meant is the removal of API functions related to OpenColorIO Transform objects to slim it down a bit. The C API is still there.