Is it currently possible to A) export an attribute macro from a proc-macro crate and then B) use the attribute macro to generate code?
Question B appears to be a "yes", but with A, I am still uncertain. I get compile errors when I try to import an attribute-macro from an adjacent crate that has a
proc-macro = true in the cargo.toml.
In the crate which uses the attribute macro, I have
#[macro_use] extern crate my_derive_crate as normally required.