A new datatype, MPI_WCHAR, is added, for the purpose of dealing with international character sets such as Unicode.
MPI_WCHAR is a C type that corresponds to the type wchar_t defined in <stddef.h>. There are no predefined reduction operations for MPI_WCHAR.
 
 
 
 Rationale.  
 
The fact that  MPI_CHAR is associated with the C datatype   
char, which in turn is often used as a substitute for the ``missing''   
byte datatype in C makes it most natural to define this as a new datatype  
specifically for multi-byte characters.  
 ( End of rationale.)