This commit cleans out a large amount of deprecated APIs from the standard
library and some of the facade crates as well, updating all users in the
compiler and in tests as it goes along.
This trait has proven quite useful when defining marker traits to avoid the
semi-confusing `PhantomFn` trait and it looks like it will continue to be a
useful tool for defining these traits.
This trait has proven quite useful when defining marker traits to avoid the
semi-confusing `PhantomFn` trait and it looks like it will continue to be a
useful tool for defining these traits.
This is one more step towards completing #13231
This series of commits add support for default trait implementations. The changes in this PR don't break existing code and they are expected to preserve the existing behavior in the compiler as far as built-in bounds checks go.
The PR adds negative implementations of `Send`/`Sync` for some types and it removes the special cases for `Send`/`Sync` during the trait obligations checks. That is, it now fully relies on the traits check rather than lang items.
Once this patch lands and a new snapshot is created, it'll be possible to add default impls for `Send` and `Sync` and remove entirely the use of `BuiltinBound::{BoundSend,BoundSync}` for positive implementations as well.
This PR also removes the restriction on negative implementations. That is, it is now possible to add negative implementations for traits other than `Send`/`Sync`
into variance inference; fix various bugs in variance inference
so that it considers the correct set of constraints; modify infer to
consider the results of variance inference for type arguments.
Previously Send was defined as `trait Send: 'static {}`. As detailed in
https://github.com/rust-lang/rfcs/pull/458, the `'static` bound is not
actually necessary for safety, we can use lifetimes to enforce that more
flexibly.
`unsafe` code that was previously relying on `Send` to insert a
`'static` bound now may allow incorrect patterns, and so should be
audited (a quick way to ensure safety immediately and postpone the audit
is to add an explicit `'static` bound to any uses of the `Send` type).
cc #22251.
Port `core::ptr::Unique` to have `PhantomData`. Add `PhantomData` to
`TypedArena` and `Vec` as well.
As a drive-by, switch `ptr::Unique` from a tuple-struct to a struct
with fields.
This was particularly helpful in the time just after OIBIT's
implementation to make sure things that were supposed to be Copy
continued to be, but it's now creates a lot of noise for types that
intentionally don't want to be Copy.
I searched for times when we were hiding functions with # in the documentation,
and fixed them to not use it unless neccesary.
I also made random improvements whenever I changed something. For example,
I changed Example to Examples, for consistency.
Fixes#13423
