[hkwerf]

While it's not implemented, Rust even has a keyword reserved [1] for musttail, "become": https://github.com/phi-go/rfcs/blob/guaranteed-tco/text/0000...

[1] https://doc.rust-lang.org/reference/keywords.html

[discardable_dan]

And like everything else in Rust, it will forever live in the "unstable" pile of features that are required to use the language without standing on your head (looking at you, pattern matching through boxes).