in fmt v10, it does not cast unaligned<T> to T when formatting it,
instead it insists on finding a matched fmt::formatter<> specialization for it.
that's why we have FTBFS with fmt v10 when printing
these packed<T> variables with fmtlib v10.
in this change, we just cast them to the underlying types before
formatting them. because seastar::unaligned<T> does not provide
a method for accessing the raw value, neither does it provide
a type alias of the type of the underlying raw value, we have
to cast to the type without deducing it from the printed value.
Refs #13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#16167
0b69a1badc