before this change, `fmt::formatter<auth::resource_kind>` is located at
line 250 in this file, but it is used at line 130. so, {fmt} is not able
to find it:
```
/usr/include/fmt/core.h:2593:45: error: implicit instantiation of undefined template 'fmt::detail::type_is_unformattable_for<auth::resource_kind, char>'
2593 | type_is_unformattable_for<T, char_type> _;
| ^
/usr/include/fmt/core.h:2656:23: note: in instantiation of function template specialization 'fmt::detail::parse_format_specs<auth::resource_kind, fmt::detail::compile_parse_context<char>>' requested here
2656 | parse_funcs_{&parse_format_specs<Args, parse_context_type>...} {}
| ^
/usr/include/fmt/core.h:2787:47: note: in instantiation of member function 'fmt::detail::format_string_checker<char, auth::resource_kind, auth::resource_kind>::format_string_checker' requested here
2787 | detail::parse_format_string<true>(str_, checker(s));
| ^
/home/kefu/dev/scylladb/auth/resource.hh:130:29: note: in instantiation of function template specialization 'fmt::basic_format_string<char, auth::resource_kind &, auth::resource_kind &>::basic_format_string<char[65], 0>' requested here
130 | seastar::format("This resource has kind '{}', but was expected to have kind '{}'.", actual, expected)) {
| ^
/usr/include/fmt/core.h:1578:45: note: template is declared here
1578 | template <typename T, typename Char> struct type_is_unformattable_for;
| ^
```
in this change, `fmt::formatter<auth::resource_kind>` is moved up to
where `auth::resource_kind` is defined. so that it can be used by its
caller.
Refs #13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#18316
ab4de1f470