+ExecPtr Exec::unset_host()
+{
+ if (not is_assigned())
+ throw std::invalid_argument(
+ xbt::string_printf("Exec %s: the activity is not assigned to any host(s)", get_cname()));
+ else {
+ reset();
+
+ if (state_ == State::STARTED)
+ cancel();
+ vetoable_start();
+
+ return this;
+ }
+}
+