Boost library authors and maintainers are free to drop support for old C++ standards in their libraries, at any time.

This includes libraries that other Boost libraries depend on. It even includes core libraries like Boost.Core or Boost.Static_Assert.

We ask that maintainers do the right thing by all our users (which may include other Boost libraries) by announcing a future breakage at least two Boost releases in advance.

When that eventual release time arrives, if Boost libraries are broken in older standards modes due to another Boost library dropping support, it will not block the Boost release.

This means that we do not need to announce "Boost is dropping C++03" because Boost doesn't "support C++03" now as it is.

It means that you, maintainer of Boost.X, should realize that you are free to announce that "Boost.X is dropping C++XY in version 1.Z" as you see fit.

Boost in its infancy thrived because its libraries were on the cutting edge. Boost libraries today should similarly not be confined simply because other Boost libraries have chosen to depend on them.

Furthermore, as Boost release managers we support authors exercising this freedom, and do not intend to impose any restrictions on what language support they must maintain.

We will add a page to the Boost website stating the above formally.

-- The release team (Glen Fernandes, Marshall Clow)