rust/tests/ui/cast/ptr-to-trait-obj-add-auto.stderr

error[E0804]: cannot add auto trait `Send` to dyn bound via pointer cast
  --> $DIR/ptr-to-trait-obj-add-auto.rs:4:5
   |
LL |     x as _
   |     ^^^^^^ unsupported cast
   |
   = note: this could allow UB elsewhere
   = help: use `transmute` if you're sure this is sound

error[E0804]: cannot add auto traits `Send`, `Sync`, and `Unpin` to dyn bound via pointer cast
  --> $DIR/ptr-to-trait-obj-add-auto.rs:13:5
   |
LL |     x as _
   |     ^^^^^^ unsupported cast
   |
   = note: this could allow UB elsewhere
   = help: use `transmute` if you're sure this is sound

error: aborting due to 2 previous errors

For more information about this error, try `rustc --explain E0804`.
Make `ptr_cast_add_auto_to_object` lint into hard error In Rust 1.81, we added a FCW lint (including linting in dependencies) against pointer casts that add an auto trait to dyn bounds. This was part of work making casts of pointers involving trait objects stricter which was needed to restabilize trait upcasting. We considered just making this a hard error at the time, but opted against it due to breakage found by crater. This breakage was mostly due to the `anymap` crate which has been a persistent problem for us. It's now a year later, and the fact that this is not yet a hard error is giving us pause about stabilizing arbitrary self types and `derive(CoercePointee)`. So let's now make a hard error of this. 2025-02-09 06:08:59 +00:00			error[E0804]: cannot add auto trait `Send` to dyn bound via pointer cast
			`--> $DIR/ptr-to-trait-obj-add-auto.rs:4:5`
Add more checks for pointers with vtable meta The rules for casting `mut X<dyn A>` -> `mut Y<dyn B>` are as follows: - If `B` has a principal - `A` must have exactly the same principal (including generics) - Auto traits of `B` must be a subset of autotraits in `A` Note that `X<_>` and `Y<_>` can be identity, or arbitrary structs with last field being the dyn type. The lifetime of the trait object itself (`dyn ... + 'a`) is not checked. This prevents a few soundness issues with `#![feature(arbitrary_self_types)]` and trait upcasting. Namely, these checks make sure that vtable is always valid for the pointee. 2024-02-12 21:24:48 +00:00			`\|`
			`LL \| x as _`
Make `ptr_cast_add_auto_to_object` lint into hard error In Rust 1.81, we added a FCW lint (including linting in dependencies) against pointer casts that add an auto trait to dyn bounds. This was part of work making casts of pointers involving trait objects stricter which was needed to restabilize trait upcasting. We considered just making this a hard error at the time, but opted against it due to breakage found by crater. This breakage was mostly due to the `anymap` crate which has been a persistent problem for us. It's now a year later, and the fact that this is not yet a hard error is giving us pause about stabilizing arbitrary self types and `derive(CoercePointee)`. So let's now make a hard error of this. 2025-02-09 06:08:59 +00:00			`\| ^^^^^^ unsupported cast`
Add more checks for pointers with vtable meta The rules for casting `mut X<dyn A>` -> `mut Y<dyn B>` are as follows: - If `B` has a principal - `A` must have exactly the same principal (including generics) - Auto traits of `B` must be a subset of autotraits in `A` Note that `X<_>` and `Y<_>` can be identity, or arbitrary structs with last field being the dyn type. The lifetime of the trait object itself (`dyn ... + 'a`) is not checked. This prevents a few soundness issues with `#![feature(arbitrary_self_types)]` and trait upcasting. Namely, these checks make sure that vtable is always valid for the pointee. 2024-02-12 21:24:48 +00:00			`\|`
Make `ptr_cast_add_auto_to_object` lint into hard error In Rust 1.81, we added a FCW lint (including linting in dependencies) against pointer casts that add an auto trait to dyn bounds. This was part of work making casts of pointers involving trait objects stricter which was needed to restabilize trait upcasting. We considered just making this a hard error at the time, but opted against it due to breakage found by crater. This breakage was mostly due to the `anymap` crate which has been a persistent problem for us. It's now a year later, and the fact that this is not yet a hard error is giving us pause about stabilizing arbitrary self types and `derive(CoercePointee)`. So let's now make a hard error of this. 2025-02-09 06:08:59 +00:00			`= note: this could allow UB elsewhere`
			= help: use `transmute` if you're sure this is sound
Add more checks for pointers with vtable meta The rules for casting `mut X<dyn A>` -> `mut Y<dyn B>` are as follows: - If `B` has a principal - `A` must have exactly the same principal (including generics) - Auto traits of `B` must be a subset of autotraits in `A` Note that `X<_>` and `Y<_>` can be identity, or arbitrary structs with last field being the dyn type. The lifetime of the trait object itself (`dyn ... + 'a`) is not checked. This prevents a few soundness issues with `#![feature(arbitrary_self_types)]` and trait upcasting. Namely, these checks make sure that vtable is always valid for the pointee. 2024-02-12 21:24:48 +00:00
Make `ptr_cast_add_auto_to_object` lint into hard error In Rust 1.81, we added a FCW lint (including linting in dependencies) against pointer casts that add an auto trait to dyn bounds. This was part of work making casts of pointers involving trait objects stricter which was needed to restabilize trait upcasting. We considered just making this a hard error at the time, but opted against it due to breakage found by crater. This breakage was mostly due to the `anymap` crate which has been a persistent problem for us. It's now a year later, and the fact that this is not yet a hard error is giving us pause about stabilizing arbitrary self types and `derive(CoercePointee)`. So let's now make a hard error of this. 2025-02-09 06:08:59 +00:00			error[E0804]: cannot add auto traits `Send`, `Sync`, and `Unpin` to dyn bound via pointer cast
Use `DiagSymbolList` for a lint diagnostic 2024-07-04 16:46:00 +02:00			`--> $DIR/ptr-to-trait-obj-add-auto.rs:13:5`
			`\|`
			`LL \| x as _`
Make `ptr_cast_add_auto_to_object` lint into hard error In Rust 1.81, we added a FCW lint (including linting in dependencies) against pointer casts that add an auto trait to dyn bounds. This was part of work making casts of pointers involving trait objects stricter which was needed to restabilize trait upcasting. We considered just making this a hard error at the time, but opted against it due to breakage found by crater. This breakage was mostly due to the `anymap` crate which has been a persistent problem for us. It's now a year later, and the fact that this is not yet a hard error is giving us pause about stabilizing arbitrary self types and `derive(CoercePointee)`. So let's now make a hard error of this. 2025-02-09 06:08:59 +00:00			`\| ^^^^^^ unsupported cast`
Use `DiagSymbolList` for a lint diagnostic 2024-07-04 16:46:00 +02:00			`\|`
Make `ptr_cast_add_auto_to_object` lint into hard error In Rust 1.81, we added a FCW lint (including linting in dependencies) against pointer casts that add an auto trait to dyn bounds. This was part of work making casts of pointers involving trait objects stricter which was needed to restabilize trait upcasting. We considered just making this a hard error at the time, but opted against it due to breakage found by crater. This breakage was mostly due to the `anymap` crate which has been a persistent problem for us. It's now a year later, and the fact that this is not yet a hard error is giving us pause about stabilizing arbitrary self types and `derive(CoercePointee)`. So let's now make a hard error of this. 2025-02-09 06:08:59 +00:00			`= note: this could allow UB elsewhere`
			= help: use `transmute` if you're sure this is sound
Use `DiagSymbolList` for a lint diagnostic 2024-07-04 16:46:00 +02:00
Make `ptr_cast_add_auto_to_object` lint into hard error In Rust 1.81, we added a FCW lint (including linting in dependencies) against pointer casts that add an auto trait to dyn bounds. This was part of work making casts of pointers involving trait objects stricter which was needed to restabilize trait upcasting. We considered just making this a hard error at the time, but opted against it due to breakage found by crater. This breakage was mostly due to the `anymap` crate which has been a persistent problem for us. It's now a year later, and the fact that this is not yet a hard error is giving us pause about stabilizing arbitrary self types and `derive(CoercePointee)`. So let's now make a hard error of this. 2025-02-09 06:08:59 +00:00			`error: aborting due to 2 previous errors`
Use `DiagSymbolList` for a lint diagnostic 2024-07-04 16:46:00 +02:00
Make `ptr_cast_add_auto_to_object` lint into hard error In Rust 1.81, we added a FCW lint (including linting in dependencies) against pointer casts that add an auto trait to dyn bounds. This was part of work making casts of pointers involving trait objects stricter which was needed to restabilize trait upcasting. We considered just making this a hard error at the time, but opted against it due to breakage found by crater. This breakage was mostly due to the `anymap` crate which has been a persistent problem for us. It's now a year later, and the fact that this is not yet a hard error is giving us pause about stabilizing arbitrary self types and `derive(CoercePointee)`. So let's now make a hard error of this. 2025-02-09 06:08:59 +00:00			For more information about this error, try `rustc --explain E0804`.