+// Teach the compiler that some code path is unreacheable:
+#if defined(__has_builtin)
+ #if __has_builtin(__builtin_unreachable)
+ #define XBT_UNREACHABLE() __builtin_unreachable()
+ #else
+ #include <stdlib.h>
+ #define XBT_UNREACHABLE() abort()
+ #endif
+#elif (__GNUC__ > 4) || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5)
+ #define XBT_UNREACHABLE() __builtin_unreachable()
+#else
+ #include <stdlib.h>
+ #define XBT_UNREACHABLE() abort()
+#endif
+