[libcxx-commits] [libcxx] Adds back special-case for booleans in std::variant gated by _LIBCPP_ENABLE_NARROWING_CONVERSIONS_IN_VARIANT. (PR #73121)

[via libcxx-commits]

alexfh wrote:

> Can you explain why you want to make this change? [170810f](https://github.com/llvm/llvm-project/commit/170810fca6ee0f0e9a5b60c83122127d68bcc7ec) made our implementation conforming, and this makes us non-conforming with the macro defined.

The problem is that 170810fca6ee0f0e9a5b60c83122127d68bcc7ec causes not just compilation errors, but also runtime behavior change. We see thousands of build breakages and hundreds or even thousands of test failures root-causing to this change. Bringing libc++ to conformance is a good cause, but this was a breaking change with very widespread effect.

https://github.com/llvm/llvm-project/pull/73121