Meeting proposal: rename "object safety" to "dyn compatibility"

[notriddle]

Summary

Instead of calling them "object safe," refer to traits that support vtables as being "dyn compatible."

Background reading

https://internals.rust-lang.org/t/object-safety-is-a-terrible-term/21025

About this issue

This issue corresponds to a lang-team design meeting proposal. It corresponds to a possible topic of discussion that may be scheduled for deeper discussion during one of our design meetings.

[joshtriplett]

We talked about this at today's meeting, and we're generally in favor of making this change. Starting an FCP to confirm.

@rfcbot merge

[rfcbot]

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

• @joshtriplett
• @nikomatsakis
• @pnkfelix
• @scottmcm
• @tmandry
• @traviscross

No concerns currently listed.

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!

cc @rust-lang/lang-advisors: FCP proposed for lang, please feel free to register concerns.
See this document for info about what commands tagged team members can give me.

[traviscross]

@rfcbot reviewed

I agree that dyn compatible is a better term to describe which traits may be used with dyn. Specifically, I'd probably frame it that dyn-safety / trait object safety is something that Rust ensures, and that what it requires from users is that they write dyn compatible traits.

[rfcbot]

🔔 This is now entering its final comment period, as per the review above. 🔔

[traviscross]

cc @ehuss