There's another library called repr which claims to handle C arrays properly: https://godbolt.org/z/vbz639n4d. Can this solution be used to handle C arrays properly in boost pfr?
Here's a link to the implementation as it appears in the source tree (rather than amalgamated): https://github.com/Tsche/repr/blob/master/include/librepr/reflection/detail/arity.h