Hi Tom,
Thanks a lot for sharing the notes.
In the meantime, I progressed a few things:
1. `std::array` is a structural type indeed, but there is no way to make the code below work:
template<std::array Txt>
class Foo {};
Foo<"abc"> foo;
To make it work, we would need dedicated deduction guides for this use case in `std::array` or a UDL, which are not going to happen. Also, the lack of overloaded operators with zero-ended-strings semantics (e.g., `op+`) makes it harder to work with it.
2. All enumerations of `unit_symbol_formatting` are now `std::int8_t` per Victor's suggestions.
Best
Mat