Clang-formatting - what should be included, what should be removed, future additions

[ajedele]

The clang-tidy is currently used to check the code submitted to GitHub. There are several features that are of great benefit and some that are more cumbersome or above the skill-level of average R3BRoot user.

In lieu of the conversation from last Thursday, the point of this post is to start the conversation around the clang-format.

In my opinion, I think there are a few easy things that make sense:

• removing the Root nomenclature for variables (double vs. Double_t)
• using c++ libraries when possible (for example std::vector vs. TVector, array vs TArray)

When it comes to Root classes, we need to be highly realistic. Root will be the staple of our coding until CERN stops supporting it. Therefore, the clang-tidy should not 'punish' users for using TF1s, TH1Ds, etc.