[boost] Re: [multi_index] upgrade to C++11 and potential backwards compatibility issues

On 20 Dec 2025 23:45, Joaquin M López Muñoz via Boost wrote:

Hi,

Boost.MultiIndex has been upgraded to require C++11 a minimum, and in the process the library has been refactored to no longer use Boost.MPL and Boost.Preprocessor. The changes, benefits and potential backwards compatibility issues are explained in this external article:

https://bannalia.blogspot.com/2025/12/boostmultiindex-refactored.html

If you're a Boost.MultiIndex user please test this upgraded version in advance of the target Boost 1.91 release (develop branch of boostorg/multi_index) so that we have time to fix any problem that may arise. Thank you!

Looks like it broke Boost.Flyweight. https://github.com/boostorg/flyweight/issues/24