Use anonymous namespace to avoid duplicate symbols

[wmtan]

Bug fix. Totally technical.
In RecoEgamma/EgammaTools/plugins, there are free function templates in different files that have the same signature. These are violations of the ODR (one definition rule).
The reason this problem has not yet been seen before is that the function templates in question are declared "inline". However, "inline" is only a suggestion to the compiler. When compiled in debug mode (-O0), in-lining was apparently turned off. This did not cause a link error, as function templates are not instantiated until run time. However, it caused the wrong function to be called in several cases, causing relvals 4.53, 135.4, and 1330.0 to fail.
The fix is to put the templates inside an anonymous namespace, so each template is not seen outside the compilation unit. This fixes the failing relvals.

[cmsbuild]

A new Pull Request was created by @wmtan for CMSSW_7_5_X.

Use anonymous namespace to avoid duplicate symbols

It involves the following packages:

RecoEgamma/EgammaTools

@cmsbuild, @cvuosalo, @slava77 can you please review it and eventually sign? Thanks.
@Sam-Harper, @lgray this is something you requested to watch as well.
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@Degano you are the release manager for this.
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[slava77]

@cmsbuild please test

[cmsbuild]

The tests are being triggered in jenkins.

[cmsbuild]

+1
Tested at: 6a16ed7
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-11069/7851/summary.html

[cmsbuild]

Comparison is ready
https://cmssdt.cern.ch/SDT/jenkins-artifacts/pull-request-integration/PR-11069/7851/summary.html

[slava77]

+1

for #11069 6a16ed7

• changes are almost as in 76X version
  • RecoEgamma/EgammaTools/plugins/EGPfIsolationModifier.cc file is still not in the release, to be merged with EGM IDs for MiniAOD Reprocessing (75X) #10599
• jenkins tests pass and comparisons with the baseline show no difference as expected from regular builds

[cmsbuild]

This pull request is fully signed and it will be integrated in one of the next CMSSW_7_5_X IBs once checked with relvals in the development release cycle of CMSSW (tests are also fine). This pull request requires discussion in the ORP meeting before it's merged. @davidlange6, @Degano, @smuzaffar

[davidlange6]

+1