[MPI3 Fortran] Fortran extra_state argument to MPIattributefunctions

[Aleksandar Donev]

N.M. Maclaren wrote:
> While this is true, a reasonable alternative approach (which is what is
> actually done by must current implementations for MPI handles) is to use
> an integer token in Fortran, and have the using routines decode it.
Sure, if you want to stay with the dark ages, go ahead. I don't find it 
alternative to force people to write tables for encoding and decoding 
pointers in a 64 bit integer. It is called a virtual memory system and 
is already done by the operating system. For a language that supports 
pointers, there is no reason to hack integers (that is a good idea in 
scientific codes for efficiency and other considerations, but not here).
Best,
Aleks