This clarification is needed in the MPI-1 description of MPI_TYPE_SIZE, since the issue repeatedly arises. It is a clarification of the binding.
 Advice to users.
The MPI-1 Standard specifies that the output argument of
MPI_TYPE_SIZE in C is of type int. The MPI Forum
considered proposals to change this and decided to reiterate the original
( End of advice to users.)