I have updated my checkedint DUB package to work with newer compilers:
    https://code.dlang.org/packages/checkedint
There are two significant breaking changes as a part of this:

* The minimum compiler frontend version is now 2.071.

* If the `-preview=intpromote` compiler option is supplied, the return types of `safeOp.unary`, `safeOp.abs`, and the corresponding `SafeInt` methods change to match the new behavior of the built-in types. See the changelog for D 2.078:
    https://dlang.org/changelog/2.078.0.html#fix16997

I fixed all of the deprecation warnings that I could, but there are a few that can only reasonably be removed by enabling `-preview=intpromote`. These should go away naturally once `intpromote` becomes the default.

If anyone is actually using this package, please let me know either here or on GitHub if there's anything else I need to fix.