The C++ code base currently has a mix of ALL_CAPS (e.g. arrow::ValueDescr::Shape, seems to be favored in arrow::compute::), CapWords (e.g. arrow::StatusCode), and kCapWords (e.g. arrow::DecimalStatus, not common in arrow:: but used in gandiva:: and technically what the Google style guide recommends[1]).
I don't know that it is worth fixing any existing code but perhaps we should be consistent going forwards? In a recent PR of mine Antoine pointed out that ALL_CAPS can clash with macro names. That seems reasonable so my preference would be AllCaps. If we can reach some consensus I'll put a PR together to update the style guide docs [1] https://google.github.io/styleguide/cppguide.html#Enumerator_Names -Weston
