Hi everyone, I would like to gauge interest in a library I've been working on called Flags, which provides type-safe, non-intrusive bitwise operators for C++ enumerations. The primary goal of the library is to make the usage of flag-like enums safer by preventing accidental mixing of different types while still allowing them to be used with standard bitwise logic. A preliminary version of the library was presented here two years ago. The reception was positive and led to an enlightening discussion with Andrey Semashev, who pointed out several flaws in the design — notably potential ODR violations and the need for argument-dependent lookup (ADL) of operators. An enhanced version was then presented at C++Now 2024, where it was also well-received. After incorporating all feedback and allowing another year for the library to mature within internal projects, I have decided to resubmit it here. Key Features: * Type-safety: Prevents accidental mixing of different enum types and disables built-in arithmetic operators for enabled enums to turn logical errors into compilation errors. * Non-intrusive: Can be opted-in for existing enums (both scoped and unscoped) without modifying their definition. Simple macro-based opt-in via BOOST_FLAGS(...) [currently intended name]. * Compile-Time Friendly: Everything is constexpr, making it usable in template arguments. * Zero Overhead: Designed as zero-cost abstraction in optimized builds. * Distinguishes between flag-sets and their negations at the type level (based on a sound mathematical model). * Requires at least C++11, uses newer features if present Resources: * Documentation: https://tobias-loew.github.io/flags/ * GitHub Repository: https://github.com/tobias-loew/flags * Boost-Mail-Archive first presentation: https://lists.boost.org/archives/list/boost@lists.boost.org/thread/EZXQFJWA5... * C++Now 2024 Presentation: "Fun with Flags", https://www.youtube.com/watch?v=2dzWasWblRc * Godbolt Example: https://godbolt.org/z/PPoKaGrzc I am interested in hearing if the community sees a place for this in Boost or has any feedback on the design. Best regards, Tobias Loew