MPI_Comm comm)
#define COLL_ALLGATHERS(action, COLL_sep) \
-COLL_NOTHING(COLL_APPLY(action, COLL_ALLGATHER_SIG, 2dmesh) COLL_sep) \
-COLL_NOTHING(COLL_APPLY(action, COLL_ALLGATHER_SIG, 3dmesh) COLL_sep) \
-COLL_NOTHING(COLL_APPLY(action, COLL_ALLGATHER_SIG, bruck) COLL_sep) \
+COLL_APPLY(action, COLL_ALLGATHER_SIG, 2dmesh) COLL_sep \
+COLL_APPLY(action, COLL_ALLGATHER_SIG, 3dmesh) COLL_sep \
+COLL_APPLY(action, COLL_ALLGATHER_SIG, bruck) COLL_sep \
COLL_APPLY(action, COLL_ALLGATHER_SIG, GB) COLL_sep \
COLL_APPLY(action, COLL_ALLGATHER_SIG, loosely_lr) COLL_sep \
COLL_APPLY(action, COLL_ALLGATHER_SIG, lr) COLL_sep \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, NTS) COLL_sep \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, rab1) COLL_sep \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, rab2) COLL_sep \
-COLL_NOTHING(COLL_APPLY(action, COLL_ALLREDUCE_SIG, rab_rdb) COLL_sep) \
+COLL_APPLY(action, COLL_ALLREDUCE_SIG, rab_rdb) COLL_sep \
COLL_NOTHING(COLL_APPLY(action, COLL_ALLREDUCE_SIG, rab_reduce_scatter) COLL_sep) \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, rab_rsag) COLL_sep \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, rdb) COLL_sep \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, smp_binomial) COLL_sep \
-COLL_NOTHING(COLL_APPLY(action, COLL_ALLREDUCE_SIG, smp_binomial_pipeline) COLL_sep) \
+COLL_APPLY(action, COLL_ALLREDUCE_SIG, smp_binomial_pipeline) COLL_sep \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, smp_rdb) COLL_sep \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, smp_rsag) COLL_sep \
COLL_APPLY(action, COLL_ALLREDUCE_SIG, smp_rsag_lr) COLL_sep \