It would be nice to be able to compile all Xr0 code directly with a regular C compiler though. It's more convenient than running it through a program, which is a bit of a headache sometimes.

For complicated annotations, instead of

  void foo(int* x) ~ [ free(x); ];

They could do:

   #include <xr0.h>
   void foo(int* x) XR0( free(x); );

Then this will compile in a standard C compiler (assuming the XR0 macro is defined properly in xr0.h)