/*! take a vector of s4u::ExecPtr and return when one of them is finished.
* The return value is the rank of the first finished ExecPtr. */
static int wait_any(std::vector<ExecPtr>* execs) { return wait_any_for(execs, -1); }
/*! take a vector of s4u::ExecPtr and return when one of them is finished.
* The return value is the rank of the first finished ExecPtr. */
static int wait_any(std::vector<ExecPtr>* execs) { return wait_any_for(execs, -1); }