Macro stakker::ret_failthru

macro_rules! ret_failthru {
    ($cx:expr, $msg:literal) => { ... };
    ($cx:expr, $fmt:literal $(, $arg:expr)*) => { ... };
    ($cx:expr, $error:expr) => { ... };
}

Create a Ret instance that passes through actor failure

ret_failthru!(cx, "format...", fmt-args...);
ret_failthru!(cx, "literal...");
ret_failthru!(cx, error);

This is designed to be used as a termination notifier for a child actor in the actor! or actor_new! call. It receives an Option<StopCause> and terminates the current actor if the child actor failed or lost connection. So this can be used in actors to cascade failure upwards until it reaches an ancestor that can handle it.

Note that this does not terminate this actor if the child actor terminated successfully or if it was killed or dropped. Only failure or lost connection is passed on as a failure. If the child is never expected to terminate early, consider using ret_fail! instead, or writing your own termination handler if the situation is more complex.

The arguments are treated as for fail!, calling on to Cx::fail, Cx::fail_str or Cx::fail_string.

Note that errors are not normally chained in Stakker, i.e. the failure wouldn’t normally contain details of the failures which lead to that failure. The detailed history of a failure can be analyzed by running with the logger feature enabled, and looking at Open and Close events.