Discuss Rkyv 0.8 migration

[ThierryBerger]

pull request linked to #4 ; only here to provide more code-backed discussion through macro expand.

[ThierryBerger]

This line errors out with:

error[E0308]: mismatched types
   --> rkyv_wrappers/src/expanded.rs:33:17
    |
30  |             <CustomPhantom<T> as ::rkyv::with::ArchiveWith<PhantomData<T>>>::resolve_with(
    |             ----------------------------------------------------------------------------- arguments to this function are incorrect
...
33  |                 field_out,
    |                 ^^^^^^^^^ expected `Place<...>`, found `Place<PhantomData<T>>`
    |
    = note: expected struct `Place<<CustomPhantom<T> as ArchiveWith<PhantomData<T>>>::Archived>`
               found struct `Place<PhantomData<T>>`
    = help: consider constraining the associated type `<CustomPhantom<T> as ArchiveWith<PhantomData<T>>>::Archived` to `PhantomData<T>` or calling a method that returns `<CustomPhantom<T> as ArchiveWith<PhantomData<T>>>::Archived`
    = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html
note: associated function defined here
   --> /home/tb/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/rkyv-0.8.10/src/with.rs:114:8
    |
114 |     fn resolve_with(
    |        ^^^^^^^^^^^^