static int create_contiguous(int count, MPI_Datatype old_type, MPI_Aint lb, MPI_Datatype* new_type);
static int create_vector(int count, int blocklen, int stride, MPI_Datatype old_type, MPI_Datatype* new_type);
static int create_hvector(int count, int blocklen, MPI_Aint stride, MPI_Datatype old_type, MPI_Datatype* new_type);
static int create_contiguous(int count, MPI_Datatype old_type, MPI_Aint lb, MPI_Datatype* new_type);
static int create_vector(int count, int blocklen, int stride, MPI_Datatype old_type, MPI_Datatype* new_type);
static int create_hvector(int count, int blocklen, MPI_Aint stride, MPI_Datatype old_type, MPI_Datatype* new_type);