[Mpi-forum] First reading: Remove NBC C++ bindings

[Jeff Squyres]

On Apr 14, 2011, at 8:54 AM, Jeff Hammond wrote:

> I thought the Forum decided to un-deprecate the C++ bindings, or at
> least had a straw vote expressing intent to do this.  If that is the
> case, C++ bindings should be defined for all 3.0 functionality.

I'm unaware of any such decision being made.

And to clarify: the new ticket is to make the NBC stuff consistent with everything else that is happening in MPI-3.0 (i.e., no new C++ bindings).  It's only due to a quirk of timing that the MPI-3.0 NBC text was accepted with new functions that included C++ bindings.

> I come to less than half the Forum meetings, so can someone point me
> to the content that explains when and how the tide turned back towards
> MPI not treating C++ as a first-class programming language?

Your statement isn't quite fair -- MPI does nothing to disqualify C++ applications.  You can (obviously) use the C bindings in a C++ application.  

And also to be specific: the C++ bindings are not being withdrawn; they are deprecated, meaning that they *might* be removed someday (not by me, and I don't know anyone who is willing to undertake the effort -- it would be a LOT of text to edit).  And no new C++ bindings will be introduced.

See https://svn.mpi-forum.org/trac/mpi-forum-web/ticket/150 for some details about the 2.2 deprecation of the C++ bindings.  The general feelings were:

- the C++ bindings have caused *considerable* maintenance over the years (including several ill-informed / incorrect errata email votes in the late '90s)
- the C++ bindings provide very little semantic difference over the C bindings
- plans for the C++ bindings to be building blocks for more expressive C++ class libraries essentially failed (e.g., Boost.MPI uses the C bindings)
- more expressive C++ MPI class library functionality is both out of scope of the MPI specification and is available elsewhere

-- 
Jeff Squyres
jsquyres at cisco.com
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