This crate is based on https://cprimozic.net/blog/writing-a-hashmap-to-struct-procedural-macro-in-rust/
There was sadly no crate available, so I had to make my own :(
I made some improvements to the code and ported it to a newer version of
syn. For example the [FromMap] trait doesn't need a type parameter
and the [HashMap] should contain a static str (field names should be known
at compile time).