On Sep 22 2012, Supalov, Alexander wrote:

Indeed. The road goes on and on. :)

Yes, but the real questions are: a) Is this a sensible road to follow, or does it lead to perdition? It isn't always a good way to provide functionality - vide Fortran versus C++, where they are comparably flexible, but the latter is 3-5 times as large as the former. b) Would it be better to establish defined halting places, for the majority of users and a very large number of implementors who do not want to follow the path to the end? For the majority of uses, one can achieve 99% of the functionality for 10% of the implementation effort. I haven't investigated implementations in any depth recently, but recent quick looks confirms that quite a few MPI features are NOT available in all of the major ones. I know that is true for heterogeneous systems, and the more extreme threading options, but there are quite a few other areas where I should be flabberghasted if it were not. And, of course, at least some of the almost-unused features don't actually work quite right, but don't get fixed because nobody gives a damn .... Regards, Nick Maclaren.