[`idna::domain_to_ascii` docs](https://docs.rs/idna/latest/idna/fn.domain_to_ascii.html) say: > This function exists for backward-compatibility. Consider using [`domain_to_ascii_cow`](https://docs.rs/idna/latest/idna/fn.domain_to_ascii_cow.html) instead. In the process, an `idna::AsciiDenyList` argument will be added. `EMPTY` would retain the previous behavior; `URL` may be preferred in some cases.
idna::domain_to_asciidocs say:In the process, an
idna::AsciiDenyListargument will be added.EMPTYwould retain the previous behavior;URLmay be preferred in some cases.