Revert "Replacing C-style arrays with std::array"

[davidlange6]

Reverts #15241

[cmsbuild]

A new Pull Request was created by @davidlange6 (David Lange) for CMSSW_8_1_X.

It involves the following packages:

DataFormats/HcalRecHit

@cmsbuild, @cvuosalo, @slava77, @davidlange6 can you please review it and eventually sign? Thanks.
@mariadalfonso this is something you requested to watch as well.
@slava77, @smuzaffar you are the release manager for this.

cms-bot commands are list here #13028

[slava77]

@cmsbuild please test

just to double-check there was no follow up dependent code anywhere [there shouldn't be]

[cmsbuild]

The tests are being triggered in jenkins.
https://cmssdt.cern.ch/jenkins/job/ib-any-integration/14262/console

[cmsbuild]

+1
Tested at: 86f675d
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15305/14262/summary.html

The following merge commits were also included on top of IB + this PR after doing git cms-merge-topic:
a08ea99
0fc09d4
9559a55
713ac2f
130aca9
163c0ef
You can see more details here:
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15305/14262/git-log-recent-commits
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15305/14262/git-merge-result

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-15305/14262/summary.html

[slava77]

+1

for #15305 86f675d

• the feature (std::array) is not supported by ROOT I/O. pre-revert version was tested already, there are no follow up dependencies.

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_8_1_X IBs (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @slava77, @davidlange6, @smuzaffar

[davidlange6]

+1