constexpr unsigned MPI_REQ_ACCUMULATE = 0x400;
constexpr unsigned MPI_REQ_GENERALIZED = 0x800;
constexpr unsigned MPI_REQ_COMPLETE = 0x1000;
+constexpr unsigned MPI_REQ_BSEND = 0x2000;
enum class SmpiProcessState { UNINITIALIZED, INITIALIZING, INITIALIZED /*(=MPI_Init called)*/, FINALIZED };