RFC: JEP JDK-8208089: Implement C++14 Language Features

[Kim Barrett]

> On Oct 4, 2018, at 9:17 AM, Aleksei Voitylov <aleksei.voitylov at bell-sw.com> wrote:
> 
> Kim,
> 
> Thank you for posting this. It's an important step to make. I wanted to clarify a couple of points:
> 
> 1. Since this is infrastructure JEP, is the version of JDK which will undergo such changes going to be some future version or does it apply to past versions as well? I'm concerned with how we can simplify security backports to 8u which (I currently assume) is not subject to this change.

Future version (perhaps as soon as JDK 12).  I don't think there is
any desire to backport this change.  And yes, introducing the use of
new language features will make backports even more interesting than
they already are.  That seems unavoidable if we're going to pursue
this direction.

> 2. Which versions of GCC do you tentatively consider at this point? Non-x86 ports may have a problem upgrading to a specific version of GCC which the shared code will use and may need additional lead time to adjust.

I think our (ad hoc) testing has been limited to gcc 7.x. But looking
at the gcc language conformance tables and release notes, gcc 5.x
might be good enough, and gcc 6.x seems fairly likely sufficient. Of
course, older versions are more likely to have bugs in some of these
new features. Updating the minimum supported versions for gcc and
clang are noted as TBD in the JEP.