Official C Challenge ①

Task:  Come up with an extension to the C programming language.  Provide a clear description of the extension, and a code sample that clearly shows what the extension is intended to do.

Prize:  (Winning criteria are not specified.)  The winner will have his extension featured in the C11 language standard.

My entry:  ... Sorry, I think C is perfect in every way already.

#define /regexp/ /replacement/
real varargs thats are actually built-in and useable like JavaScript args object.
builtin typeof/sizeof for pointers,objects and arrays with real size of allocated memory. Not the joke that is current C sizeof.