Hi all,
  I submitted a PR for DMD to add categorization for warnings:
https://github.com/D-Programming-Language/dmd/pull/5592

It's been shot down by Walter for DMD.
However, the spec says that warnings are not part of the spec, so LDC can do freely what it wants. I submitted the PR first to DMD because it needs front-end changes. If LDC incorporates this, I think the diff with the DMD front-end would be manageable: for the largest part it is all "warning(...)" calls for which the category needs to be added. So for merge conflicts, it is easy to see what the correct merge will be, and for new warnings one would have to decide on a warning category.

What do you guys think?

(currently, compiling with warnings is not possible for the Weka codebase (they use LDC, not DMD): there is way too much warning spam from the statement-not-reachable warning and the workaround is terrible/impossible)

-Johan