For the latest documentation on Visual Studio 2017 RC, see Visual Studio 2017 RC Documentation.
warning C28235: The function cannot stand alone as an annotation
This warning indicates that an attempt was made to use a function that was not declared to be an annotation in an annotation context. This includes using a primitive operation (PrimOp) in a standalone context. This should not be possible if the standard macros are being used for annotations. This warning is not expected to be seen in typical use.