On Wed, Feb 16, 2022 at 10:24 AM Gregory Farnum <gfarnum@xxxxxxxxxx> wrote: > > On Wed, Feb 16, 2022 at 7:17 AM Casey Bodley <cbodley@xxxxxxxxxx> wrote: > > > > thanks Greg, > > > > On Tue, Feb 15, 2022 at 8:51 PM Gregory Farnum <gfarnum@xxxxxxxxxx> wrote: > > > > > > On Thu, Feb 10, 2022 at 8:36 AM Casey Bodley <cbodley@xxxxxxxxxx> wrote: > > > > > > > > the R release could be a good opportunity to make the switch to c++20 > > > > > > > > gcc and clang both track their support for c++20 features over > > > > compiler versions in: > > > > https://gcc.gnu.org/projects/cxx-status.html#cxx20 > > > > https://clang.llvm.org/cxx_status.html#cxx20 > > > > > > > > thanks to the dev toolset in rhel/centos, we should already have > > > > access to compilers that support c++20. for ubuntu, focal is still on > > > > gcc-9 which doesn't understand -std=c++20 at all, but clang-10 does > > > > > > > > if we're willing to switch our ubuntu builds to clang, we could start > > > > experimenting with c++20 on master now. otherwise, we can wait for the > > > > jammy release in april > > > > > > Don't forget we also need to keep building for older distros. I know > > > > can we be more specific about this requirement? are you saying that > > the R release still needs to build on ubuntu focal? or that our > > octopus/pacific/quincy releases do? > > I was thinking we need to maintain support for Ubuntu 20.04 in our > next release, yeah. But that may not be right; I guess we generally > try and support the most recent LTS in our new branches. So maybe this > is a non-issue? > > > > > > it's supposed to be possible and sometimes we've managed to > > > cross-build, but it always seems to be hit-or-miss on any given > > > distro/compiler version. > > > > i'm not sure what you mean by cross-build here - is that about CI > > using different distros/compilers depending on the ceph branch? > > I mean you can technically build for eg Focal in a Jammy compiler to > get support for those new compiler features. But it's hard to > maintain. okay thanks, i see what you mean. i think it would be ideal if we could drop focal packages from all of our upstream releases. but if we can't do that yet, we could continue building earlier releases in focal so long as we avoid backporting any changes that require c++20. i believe that's how we handled the switches to c++11 and 17 in the past. though if we *can* drop focal entirely, that would make it a lot easier to adopt the new c++20 features > -Greg > > > > > > That would be my main concern. > > > -Greg > > > > > > > > > > > in the longer term, i'd love to take advantage of c++20's modules to > > > > speed up ceph builds, but it could take another year or so before > > > > cmake and the compilers support everything we need > > > > > > > > are there any other concerns or obstacles to making this switch? > > > > > > > > _______________________________________________ > > > > Dev mailing list -- dev@xxxxxxx > > > > To unsubscribe send an email to dev-leave@xxxxxxx > > > > > > > > > > _______________________________________________ Dev mailing list -- dev@xxxxxxx To unsubscribe send an email to dev-leave@xxxxxxx
