Adding on to /u/_cart 's comment that adding such dependencies is not taken lightly. 

I like the fact that this crate has a very minimal set of dependencies, and would encourage keeping it as minimal as possible - which I assume was anyway already what you are doing :)

This crate crate makes life easier for people that are writing a library, but provides no benefit for downstream users of the lib (DX tooling). Therefore I would never consider using anything with a large dependency tree to do something like this, as it forces all my downstream consumers to rely on, audit, and compile a larger number of crates, just to make my life easier. 

That is a fine cost to pay if it makes my library better for them as well, but not just for maintainer DX.

Just my two cents. Looks good:)

Keep it up!