[boost] Coordinating Parameter 'master' merging for dependent libraries

Subject: [boost] Coordinating Parameter 'master' merging for dependent libraries
From: Edward Diener (eldiener_at_[hidden])
Date: 2019-02-01 22:16:37

I intend to merge Parameter 'develop' to 'master' for the next release 
of Boost. Cromwell Enage has done a great job of adding modern 
improvements to the Parameter library via PRs, while maintaining full 
backward compatibility with the Parameter public interface. I have 
reviewed and approved those changes and, where I have been lax, Peter 
Dimov has pointed out weaknesses in some of those changes, which 
Cromwell has corrected. The changes which Cromwell has made have also 
involved improvements in the Parameter private interface(s), which have 
entailed some updates to the 'develop' branch of some Boost libraries 
which unfortunately depended on some aspects of the Parameter private 
interface. These updates have already been made in those other library's 
'develop' branch. At this point any further possible changes for 
Parameter for a while will very likely be in the Parameter 
documentation, which requires no syncing with other libraries, so this 
is an excellent time for merging.

Since the merging for other libraries dependent on Parameter must be 
synced to the merging of Parameter from 'develop' to 'master' what is 
the best way to go about this ? Obviously I have first to merge 
Cromwell's changes from 'develop' to 'master', which is easily done. How 
should I inform other libraries that they need to merge their Parameter 
dependent 'develop' changes to 'master' ? Should I create PRs for doing 
this ? We do not normally create PRs for the 'master' branch of any 
Boost library. Should I create Issues for those other libraries and hope 
the maintainers of the other libraries will take the appropriate action 
? Or should I inform the maintainers of the other libraries in this 
thread, and prompt them to review their changes here to get them to 
merge them from 'develop' to 'master' ?

The other libraries involved are: Accumulators, Log, Convert, Lockfree, 
Signals2, and Graph. Cromwell knows more about the specific 'develop' 
changes in those libraries which need to be merged to 'master' than I 
do, since he was instrumental in creating the PRs that would allow these 
libraries to work with the updated Parameters' internals, so he may 
chime in here, but I would like to get this done so that Parameter and 
its dependent Boost libraries get properly updated for the next Boost 
release. Of course I will also plan with Cromwell update notes for 
Parameter to be part of the next release.