The C++ bindings were removed from the MPI-3.0 standard in 2012 -- they've been officially deleted for 12 years. The MPI Forum talked extensively with users about this before removing them. We held on to the C++ bindings here in Open MPI for a long time, but finally deleted them in 5.0.0.
Do you know if the packages you cited actually use the MPI C++ bindings, or are they C++ packages that happen to use MPI C bindings? One of the reasons that the Forum decided to delete the C++ bindings was because C++ app developer community overwhelmingly stated that they used the C bindings (because the C++ bindings were almost exactly a 1:1 mapping to the C bindings, and didn't offer much more/different functionality than the C bindings). There were a small number of users who actually used the MPI C++ bindings, but to my knowledge, they all migrated to the C bindings over time. ________________________________ From: devel on behalf of Orion Poplawski via devel Sent: Thursday, October 26, 2023 11:15 PM To: Open MPI Development Cc: Orion Poplawski Subject: [OMPI devel] Question about the future of C++ API support I see that openmpi 5.0.0 drops the C++ API. I'm trying to find some background on this. In particular, is this likely to be a permanent change? Also, have there been discussions of users of the C++ API? In Fedora we seem to have: MUSIC-1.1.16-13.20201002git8c6b77a.fc39.src.rpm boost-1.81.0-9.fc40.src.rpm bout++-5.0.0-11.fc40.src.rpm coin-or-Ipopt-3.14.12-2.fc39.src.rpm combblas-2.0.0-4.fc40.src.rpm freefem++-4.13-6.fc40.src.rpm ga-5.8.2-2.fc39.src.rpm gloo-0.5.0^git20230824.01a0c81-6.fc40.src.rpm gmsh-4.11.1-6.fc39.src.rpm hpx-1.9.1-1.fc40.src.rpm intel-mpi-benchmarks-2021.3-4.fc39.src.rpm libneurosim-1.2.0-8.20210110.gitafc003f.fc39.src.rpm mathgl-8.0.1-6.fc39.src.rpm mfem-4.6-1.fc40.src.rpm nest-3.4-1.fc39.src.rpm netcdf-cxx4-4.3.1-9.fc39.src.rpm netgen-mesher-6.2.2202-7.fc39.src.rpm orsa-0.7.0-61.fc39.src.rpm python-steps-3.6.0-30.fc39.src.rpm scalasca-2.6.1-2.fc38.src.rpm Thanks. -- Orion Poplawski he/him/his - surely the least important thing about me IT Systems Manager 720-772-5637 NWRA, Boulder/CoRA Office FAX: 303-415-9702 3380 Mitchell Lane or...@nwra.com Boulder, CO 80301 https://www.nwra.com/
