Coercions section: some coercions are missing

[mexus]

Currently, the Coercions (src/coercions.md) section doesn't mention the accepted and implemented (and stabilized) RFC Allow coercing non-capturing closures to function pointers.

Could it be that more coercions have been forgotten? :) I can't think of any right now, but I could have also forgotten something xD

TODO

• RFC 1558 (coercions.md: non-capturing closures to function pointers #238)
• function items to fn pointers (see below comments)

[MikailBag]

Also coercion from unnameable-function-type to fn pointer is not covered.

[mexus]

@MikailBag could you pls provide an example? I don't quite get what exactly the coercion is about..

[MikailBag]

https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=aefe8a9bcde0b9ebac8afac2d10be87d

This code shows that foo and bar have different types

[mexus]

Got it! But what about "unnameable function types"?

Ok now I got it for real :) Yeah, I guess it is worth mentioning that "function items" are implicitly coercible to function pointers, as RFC 0401 states.

[JohnTitor]

This could go to the reference as per #230 (comment).