The other point: For interoperability with other languages you often need to construct function calls at run-time. For this one needs to be able to describe types. Adding this by external libraries is always a pain because one has to carefully support the ABI of all supported architectures. A compiler can support this seamlessly. A _Typeof operator that returns a type that can be passed around and interrogated at run-time solves this in a very elegant and simple way.
