Re-export Cow from prelude

[sgrif]

Rendered

[Manishearth]

@rfcbot concern potential-cheese-extension

It occurs to me that eventually we may want to extend 🐄 to support 🥛, 🧀, and eventually 🍕. These are all delicious and it feels reasonable to assume that the community will feel a need for such delectable goods.

Is it possible to future-proof this RFC for these designs?

Furthermore, do we need to resolve whether 🍕 would be compatible with 🍍? It feels like this will be an issue down the road.

I'm reluctant to expand the scope of this RFC so broadly, however, I'd like us to get this right with a holistic design so we don't paint ourselves into a corner in the future.

[Diggsey]

[mgattozzi]

I'd like to also bring up the fact that we might actually want to implement a Cow trait here instead since many things can derive from it. While @Manishearth has brought up the fact that we might have 🥛, 🧀, and 🍕 we're also excluding a whole list of Cow derived items such as 🍦, 🎂, 🍨, and 🥞 to name a few.

[jeffparsons]

Wouldn't it be better to experiment with this out-of-tree first? Of course the obvious crate name for such an experiment would be "🐄", so crates.io will need to be taught to support Unicode crate names, too. But presumably that's pretty high on the roadmap anyway, so we could use this as an excuse to finally get that done.

[gj]

This feels like a dangerous step in the direction of emojicode, and I hope the core team will think long and hard before opening this COW (container on wheels).

[mark-i-m]

The author seems unaware that a common meaning of COW in computer science is “copy on write”, a common optimization to avoid wasting space/time when making copies of some object.

For example, in Unix-based operating systems, COW is used as an optimization when forking a process. Rather than copying the contents of all memory to the new process’s address space, the kernel orders a new computer for the user and runs the new child process on the new computer. When writes are done to the address space on the child process, they are copied to the old conputer so the kernel is aware of them (hence the name “copy on write”).

[cetra3]

Can we also export Box with 📦?

[kennytm]

Please provide the code point value for 🐄 just like 🐮, ☭, Ferris and Steve below

[kennytm]

ﾎ and ﾏ do not look like private use characters. The PUA in BMP is U+E000 – U+F8FF.

[ZhangHanDong]

I was fooled.

[Centril]

In the 2019 roadmap RFC we said that we would work to achieve:

Key ergonomic improvements

By reexporting 🐄 to the prelude, this clearly happens. As such, let's @rfcbot merge !

However...

Cow::Borrowed would be exported as U+262D HAMMER AND SICKLE, ☭. This is because ownership is theft. No further explanation is required.

This does not feel very readable. Can we use Ⓐ instead?

[pietroalbini]

This does not feel very readable. Can we use Ⓐ instead?

I feel like that should be reserved as a replacement for unsafe though.

[rodrimati1992]

I feel like that should be reserved as a replacement for unsafe though.

If we start reserving Unicode identifiers,I think ☢ would be better for marking unsafe code.

[Centril]

As such, let's @rfcbot merge !

It feels like @rfcbot has a bug or something... let's try this again.

@rfcbot merge

[rfcbot]

Team member @Centril has proposed to merge this. The next step is review by the rest of the tagged team members:

• @Amanieu
• @BurntSushi
• @Centril
• @Kimundi
• @KodrAus
• @SimonSapin
• @alexcrichton
• @aturon
• @cramertj
• @dtolnay
• @eddyb
• @joshtriplett
• @nikomatsakis
• @pnkfelix
• @scottmcm
• @sfackler
• @withoutboats

Concerns:

• potential-cheese-extension (Re-export Cow from prelude #2672 (comment))

Once a majority of reviewers approve (and at most 2 approvals are outstanding), this will enter its final comment period. If you spot a major issue that hasn't been raised at any point in this process, please speak up!

See this document for info about what commands tagged team members can give me.

[kennytm]

If we start reserving Unicode identifiers,I think ☢ would be better for marking unsafe code.

This could be confused as the replacement of std::sync::atomic though, which is pretty safe and efficient.

[Centril]

This could be confused as the replacement of std::atomic though, which is pretty safe and efficient.

There's always ☠️ { ... }.
Feels pretty clear.

[Centril]

@rfcbot concern potential-cheese-extension

on behalf of @Manishearth.

[xTibor]

Cow::Borrowed would be exported as U+262D HAMMER AND SICKLE, ☭. This is because ownership is theft. No further explanation is required.

This would mean the end of my Rust career and possibly for other people coming from the former Eastern Bloc countries. Law here [1] prohibits the public use and display of symbols of totalitarianism including all communist symbols like red stars, hammer and sickles. If this change goes through I could be punished by custodial arrest just by writing Rust code and publishing it on my public GitHub profile.

[1] https://en.wikipedia.org/wiki/Bans_on_Communist_symbols

[nagisa]

Now that it is April the 2nd and the horror of the day that was prior to this relief has subsided, I would like to comment that I actually kinda like the idea of exporting Cow. There are no portability concerns as prelude names are shadowed if another Cow is imported or defined in the scope.

[nagisa]

@rfcbot concern no-chance-to-have-this-considered-seriously??!

[cramertj]

@xTibor

This would mean the end of my Rust career and possibly for other people coming from the former Eastern Bloc countries. Law here [1] prohibits the public use and display of symbols of totalitarianism including all communist symbols like red stars, hammer and sickles. If this change goes through I could be punished by custodial arrest just by writing Rust code and publishing it on my public GitHub profile.

If it wasn't clear, this whole thread is heavily in jest and we certainly would not use a symbol like that for anything real. That said, it is perhaps worthwhile to remind folks that we're striving to be an inclusive community and want to be thoughtful about the jokes we make, especially around politics and issues with significant historical baggage.

[xTibor]

If it wasn't clear...

It was perfectly clear for me, it's just an overdramatized shitpost :)

[joshtriplett]

@nagisa I'd like to see Cow in the prelude as well (under the name Cow). (I don't think we need to re-export the constructors directly, unlike Some; it seems fine and even preferable to write Cow::Borrowed.)

I don't think re-using this thread is a good idea. Would someone like to supply a serious RFC for the re-exporting of Cow from the prelude?

[sgrif]

Yeah, I can draft a serious RFC later this week. As it's now April 2 in UTC, I'm going to shut this one down. Thanks for the fun day folks!