Boost.Endian develop branch is about to have major changes merged in as part of the preparation for a mini-review. AFAICR, the breaking changes are limited to header, class, and function name changes, but there are a lot of hopefully non-breaking changes so I could easily be wrong about that. If you are currently using Boost.Endian develop branch, you will need to change your code accordingly. It would make sense to wait a few days until the mini-review merge is complete and any fixes required by regression test failures are fixed. Thanks for your patience, --Beman