[cannam]

Aren't the Ocaml and F# examples relying on some dedicated compiler support for the format string type, though? The Idris example is interesting because its printf implementation can actually be written in Idris.

[lower]

The OCaml implementation used to be hard-coded in the type system, but has now been rewritten (in 4.02, I think) using GADTs.

https://ocaml.org/meetings/ocaml/2013/proposals/formats-as-g...

https://caml.inria.fr/mantis/view.php?id=6017

The compiler only does syntactic desugaring of format strings now.