So, let me check my understanding. If, for instance, I build something
using the 10.4 SDK, but I set the deployment version to 10.2, then my
app will be able to access the newer symbols in 10.4, but those
symbols will be NULL when my app is running on 10.2 or 10.3.
But, if on the other hand, I build using the 10.2 SDK, then I simply
won't have access to symbols introduced in 10.3 and 10.4.
Am I understanding this correctly?