On 19/05/2019 05:57, Matthew Fernandez wrote:
Some time ago I proposed PolyML switch to building with the C++11 standard [0]. The main blocking issue that surfaced was Isabelle supporting Ubuntu 12.04 which ships without a C++11-enlightened compiler. In January 2019, Makarius bumped the supported Linux release to Ubuntu 14.04 [1] which has a C++11 compiler. Are there any remaining issues preventing a migration to C++11? Do people feel strongly for or against this? The immediate benefits are similar to what I listed in my original posting:
First note that I am presently busy with the Isabelle2019 release (and will be on travel after its launch in a few weeks).
For Isabelle technology (which also includes Poly/ML), I am generally in favour to use what is both "current" and "stable" -- the precise meaning of that is up to judgment by experts, but I am not an export of C++.
This often means to use the latest release version, but sometimes latest -1. (Current examples for -1 in Isabelle: scala, Haskell stack; latest: java-11, although some users might prefer -1 here.)
BTW, for Poly/ML on Windows, there is still a slightly odd situation that its canonical build process is stuck with a very old version of g++ on MingW: http://isabelle.in.tum.de/repos/isabelle/file/acc1749c2be9/Admin/polyml/INST...
I would like to see this bumped eventually, independently of the C++11 question.
Makarius