Jeroen, Sorry, I was unclear. I'm not arguing against switching tot the new windows tool chain. Without being involved or knowing the details of any remaining difficulties, I am de facto for that.
I was specifically responding to the prospect of R packages moving to directly rely on c++17 this quickly, which Kevin brought up. R itself obviously won't be relying on c++17 since there is no c++ code in it at all I believe. Best, ~G On Mon, Apr 6, 2020 at 5:38 AM Jeroen Ooms <jer...@berkeley.edu> wrote: > On Mon, Apr 6, 2020 at 9:39 AM Gabriel Becker <gabembec...@gmail.com> > wrote: > > > > Hi Kevin, > > > > On Wed, Apr 1, 2020 at 9:36 PM Kevin Ushey <kevinus...@gmail.com> wrote: > > > > > Hello, > > > > > > FWIW, I'm excited at the prospect at seeing a new toolchain for > > > Windows, since it would imply support for C++17 and so it would become > > > easier for CRAN packages to depend on the newer C++ standard. > > > > > > > One thing to keep in mind (having been the R installation owner in such a > > place for multiple years) is that many coproprate or otherwise controlled > > compute environments may not have access to a c++17 compiler on their > > servers so making it easy for packages to rely on that is not purely > > beneficial to all parts of the R community. > > No, you're missing an important point here. On Windows, the toolchain > version is tied to the version of R and we try to keep supporting at > least one or two previous versions of R. So this means we always need > to support the legacy toolchain for a while as well. > > Hence if we switch Windows to gcc-8 for R 4.0, we still rely on > gcc-4.9 for continued support of R 3.3-3.6. This lag is what is making > the maintenance of windows system libraries painful, and why we need > to plan ahead. This is different from Linux where version of the > compiler is given by the OS and not tied to the version of R. > > If we would miss the boat again, and R 4.0 on Windows would stick with > gcc-49, this means we need to keep supporting gcc-49 as long as we > want to support R-4.0, which is at least 2022 or 2023. This would be > pretty bad. Even currently the latest versions of important system > libraries used by R packages (e.g. the gdal stack) require recent > compilers and cannot be built anymore with gcc-49. As more C++ > projects are adopting C++14/17, we can no longer update these system > libraries, missing out on all upstream fixes and advances. This would > seriously decrement the quality of the R ecosystem. > [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel