Okay, concretely, I'd like to see a translation of this real-world C++ code (taken from V8):

  #define RETURN_OBJECT_UNLESS_EXCEPTION(ISOLATE, RETURN_VALUE, RETURN_EMPTY) \
    if (!__allocation__.IsRetry()) {                                          \
      __object__ = __allocation__.ToObjectChecked();                          \
      if (__object__ == (ISOLATE)->heap()->exception()) { RETURN_EMPTY; }     \
      RETURN_VALUE;                                                           \
    }