This turns out to be a duplicate of < https://lists.boost.org/Archives/boost/2019/08/246711.php>. As suggested in that thread, the solution is to merge < https://github.com/boostorg/accumulators/pull/30> before release. Cheers, Luigi On Sat, Aug 3, 2019 at 11:40 AM Luigi Ballabio wrote:

Hello, the attached minimal file fails to compile on VC++17/19 when using Boost 1.71.0b1. It compiles successfully with Boost 1.70.0. I also attach the compiler errors.

Cheers, Luigi