@kkifonidis , @certik ,
Great effort. However based on the immediate and long-term needs of the practitioners of Fortran, any proposal toward Traits, Generics, or whatever that is based on type(T), … should really be a non-starter, absolutely dead on arrival (DOA).
All the examples in the “Traits.pdf” have “type(T) …”
I would give a firm NO to this if I had a vote!
Please review this post recommending KIND, ATTRIBUTE, RANK, and TYPE aspects. as a fundamental building block toward any enhancement toward Generics.
Given all the work in Fortran starting with ANSI FORTRAN 1966 through the current Fortran 2023 revision that has made use of TKR semantics and some ATTRIBUTE and what has been introduced with INTERFACE block, traits or generics based on “type(T)” is too limiting.
You can refine your proposal a lot better via an entity block idea.