+// If you are in a context where you know you have a current capability but
+// do not know what it is, then use this to get it. Basically this only
+// applies to "unsafe" foreign calls (as unsafe foreign calls are made with
+// the capability held).
+//
+// WARNING: There is *no* guarantee this returns anything sensible (eg NULL)
+// when there is no current capability.
+Capability *rts_unsafeGetMyCapability (void);
+