Tracking issue for enforcing object safety when coercing to an object

[nrc]

RFC PR: rust-lang/rfcs#255

[nrc]

nominating for 1.0, p-backcompat-lang

[nrc]

cc @nikomatsakis (assigned to merge the RFC PR)

[nrc]

Note for the future - I expect when we do the DST extension to trait objects we will also need to check here for some properties of associated types - that they don't include generics or Self, probably - not sure how this interacts with binding the associated types in a trait object's type though. I should check the assoc. types RFC...

[nikomatsakis]

I believe that object types must spell out the values of all associated types, at least for now. 

Niko

-------- Original message --------
From: Nick Cameron notifications@github.com
Date:09/30/2014 23:16 (GMT-05:00)
To: rust-lang/rust rust@noreply.github.com
Cc: Niko Matsakis niko@alum.mit.edu
Subject: Re: [rust] Tracking issue for enforcing object safety when coercing
to an object (#17670)

Note for the future - I expect when we do the DST extension to trait objects we will also need to check here for some properties of associated types - that they don't include generics or Self, probably - not sure how this interacts with binding the associated types in a trait object's type though. I should check the assoc. types RFC...

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[reem]

This seems like just a loss in flexibility without us really gaining much. Now we will have to split up traits that used to be simple into many small pieces just to avoid this restriction.

[alexcrichton]

cc #17704

[pnkfelix]

(leaving nominated for a week while the debate gets hashed out e.g on PR #17704 )

[pnkfelix]

leaving nominated until hopefully the weekly meeting next week.

[aturon]

See http://discuss.rust-lang.org/t/feedback-wanted-trait-objects-with-generic-self-methods/606 and http://www.reddit.com/r/rust/comments/2ihu40/feedback_wanted_trait_objects_with_generic_or/ for discussion. We're going to try to resolve this at the next weekly meeting.

[pnkfelix]

Assigning 1.0, P-backcompat-lang.