Cannot dispatch to fmt::formatter for vector types

[nextsilicon-itay-bookstein]

See here: https://clang.godbolt.org/z/b8qrPP153
Debugging this myself I think the issue is with the predicate fmt::detail::use_formatter, where vector types are neither classes, nor enums, nor unions, nor arrays.

[vitaut]

You cannot define a formatter for what is essentially a built-in type (this is similar to e.g. _BitInt(N) case). You could wrap your type in a class/struct and provide a formatter for that.