[boost] A possible date for dropping c++03 support

-----Original Message----- From: Boost On Behalf Of Tim Blechmann via Boost Sent: Sunday, August 26, 2018 3:02 PM

...

By then, all major toolchains have had solid c++11 support for at least 5 years ( I think, msvc was the last one with VS2015) and at least partial support for 7+ years (gcc 4.8, msvc 2013, clang 3.3).

compilers are one thing, compiler adoption is another ... I remember that in the past "stable" linux distributions provided compilers that were considered as "outdated", but that were used in production on HPC systems. but maybe this is less of an issue these days ..

I don't know, what distributions are used in HPC computing, but if we have a short look at common linux distributions that have any sort of long term support, then I'd say things look pretty good there: - The oldest Ubuntu version supported in 2020 will be 16.04, which ships with gcc-5 (and even 14.04 had an almost complete c++11 toolchain with gcc-4.8) - With Debian it is AFAIK Debian 8 (gcc 4.9). - I'm not sure what counts as EOL for RHEL/CentOS (that might be the problematic one), but the way I read the matrix in (https://access.redhat.com/support/policy/updates/errata), the oldest relevant distribution in 2020 (although already in Extended Life-cycle Support) will be RHEL 6 which only shipped with gcc4.4. However, RH provides the developer toolsets which include current versions of gcc. I'm not familiar with the details though, so maybe someone using RHEL could chime in here. - I'm somewhat expecting Windows to be the more problematic environment as msvc only got full c++11 support in 2015 (at least as far as you can call msvc standard conformant prior to the very latest version anyway) and extended support for 2013 ends in 2024. I think in general the question is: How many projects will there be in 2020 that (for whatever reason) still need to compile in 03 mode, but at the same time are interested in the latest version of boost? I'd expect that intersection to be very small, but of course it will be non-zero - and probably remain so for at least another decade (maybe forever). Maybe one could start survey, but in any case: does boost really want to provide free and indefinite support for those projects considering that maintenance is already a problem for some libraries? And again: Projects outside of boost can always opt to remain at the last version that had official 03 support.