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- _clang-format
I'm not sure why this is in the tree. Guessing it was a jenkins- related thing? I suspect we can drop this.
Is a similar objective than astylerc both need external programs to run maybe we need to select the less intrusibe or the best OS compatibility one
True, yes, not a bad idea. Alternatively, if we're going to have a collection of such things, they could be housed in a subdirectory somewhere. Projects will often carry configs for vim, emacs, and other editors... Having them in one place might also make it easier to spot discrepancies in each other's formatting configurations.
clang-format is similar to astyle, but it has the advantage that we can use it directly without moving the style file: from the man page, iirc clang-format looks for .clang-format files situated in parent directories of the formatted file(s).
(Side note: I'd actually be in favor of automatically running clang-format on MR if it's technically possible (a possibility would be to run it as a "test" and prevent merges of branches that make tests fail))