diff options
Diffstat (limited to 'tests/ui/feature-gates')
13 files changed, 212 insertions, 29 deletions
diff --git a/tests/ui/feature-gates/feature-gate-associated_type_bounds.rs b/tests/ui/feature-gates/feature-gate-associated_type_bounds.rs index 4e0203274..49fb10e60 100644 --- a/tests/ui/feature-gates/feature-gate-associated_type_bounds.rs +++ b/tests/ui/feature-gates/feature-gate-associated_type_bounds.rs @@ -1,6 +1,3 @@ -// compile-flags: -Zsave-analysis -// This is also a regression test for #69415 and the above flag is needed. - use std::mem::ManuallyDrop; trait Tr1 { type As1: Copy; } diff --git a/tests/ui/feature-gates/feature-gate-associated_type_bounds.stderr b/tests/ui/feature-gates/feature-gate-associated_type_bounds.stderr index 5be1d97a0..4233a8af9 100644 --- a/tests/ui/feature-gates/feature-gate-associated_type_bounds.stderr +++ b/tests/ui/feature-gates/feature-gate-associated_type_bounds.stderr @@ -1,5 +1,5 @@ error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:15:22 + --> $DIR/feature-gate-associated_type_bounds.rs:12:22 | LL | type A: Iterator<Item: Copy>; | ^^^^^^^^^^ @@ -8,7 +8,7 @@ LL | type A: Iterator<Item: Copy>; = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:19:22 + --> $DIR/feature-gate-associated_type_bounds.rs:16:22 | LL | type B: Iterator<Item: 'static>; | ^^^^^^^^^^^^^ @@ -17,7 +17,7 @@ LL | type B: Iterator<Item: 'static>; = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:23:20 + --> $DIR/feature-gate-associated_type_bounds.rs:20:20 | LL | struct _St1<T: Tr1<As1: Tr2>> { | ^^^^^^^^ @@ -26,7 +26,7 @@ LL | struct _St1<T: Tr1<As1: Tr2>> { = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:30:18 + --> $DIR/feature-gate-associated_type_bounds.rs:27:18 | LL | enum _En1<T: Tr1<As1: Tr2>> { | ^^^^^^^^ @@ -35,7 +35,7 @@ LL | enum _En1<T: Tr1<As1: Tr2>> { = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:37:19 + --> $DIR/feature-gate-associated_type_bounds.rs:34:19 | LL | union _Un1<T: Tr1<As1: Tr2>> { | ^^^^^^^^ @@ -44,7 +44,7 @@ LL | union _Un1<T: Tr1<As1: Tr2>> { = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:44:37 + --> $DIR/feature-gate-associated_type_bounds.rs:41:37 | LL | type _TaWhere1<T> where T: Iterator<Item: Copy> = T; | ^^^^^^^^^^ @@ -53,7 +53,7 @@ LL | type _TaWhere1<T> where T: Iterator<Item: Copy> = T; = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:47:22 + --> $DIR/feature-gate-associated_type_bounds.rs:44:22 | LL | fn _apit(_: impl Tr1<As1: Copy>) {} | ^^^^^^^^^ @@ -62,7 +62,7 @@ LL | fn _apit(_: impl Tr1<As1: Copy>) {} = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:49:26 + --> $DIR/feature-gate-associated_type_bounds.rs:46:26 | LL | fn _apit_dyn(_: &dyn Tr1<As1: Copy>) {} | ^^^^^^^^^ @@ -71,7 +71,7 @@ LL | fn _apit_dyn(_: &dyn Tr1<As1: Copy>) {} = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:52:24 + --> $DIR/feature-gate-associated_type_bounds.rs:49:24 | LL | fn _rpit() -> impl Tr1<As1: Copy> { S1 } | ^^^^^^^^^ @@ -80,7 +80,7 @@ LL | fn _rpit() -> impl Tr1<As1: Copy> { S1 } = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:55:31 + --> $DIR/feature-gate-associated_type_bounds.rs:52:31 | LL | fn _rpit_dyn() -> Box<dyn Tr1<As1: Copy>> { Box::new(S1) } | ^^^^^^^^^ @@ -89,7 +89,7 @@ LL | fn _rpit_dyn() -> Box<dyn Tr1<As1: Copy>> { Box::new(S1) } = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:58:23 + --> $DIR/feature-gate-associated_type_bounds.rs:55:23 | LL | const _cdef: impl Tr1<As1: Copy> = S1; | ^^^^^^^^^ @@ -98,7 +98,7 @@ LL | const _cdef: impl Tr1<As1: Copy> = S1; = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:64:24 + --> $DIR/feature-gate-associated_type_bounds.rs:61:24 | LL | static _sdef: impl Tr1<As1: Copy> = S1; | ^^^^^^^^^ @@ -107,7 +107,7 @@ LL | static _sdef: impl Tr1<As1: Copy> = S1; = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable error[E0658]: associated type bounds are unstable - --> $DIR/feature-gate-associated_type_bounds.rs:71:21 + --> $DIR/feature-gate-associated_type_bounds.rs:68:21 | LL | let _: impl Tr1<As1: Copy> = S1; | ^^^^^^^^^ @@ -115,26 +115,26 @@ LL | let _: impl Tr1<As1: Copy> = S1; = note: see issue #52662 <https://github.com/rust-lang/rust/issues/52662> for more information = help: add `#![feature(associated_type_bounds)]` to the crate attributes to enable -error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in type - --> $DIR/feature-gate-associated_type_bounds.rs:58:14 +error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in const types + --> $DIR/feature-gate-associated_type_bounds.rs:55:14 | LL | const _cdef: impl Tr1<As1: Copy> = S1; | ^^^^^^^^^^^^^^^^^^^ -error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in type - --> $DIR/feature-gate-associated_type_bounds.rs:64:15 +error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in const types + --> $DIR/feature-gate-associated_type_bounds.rs:61:15 | LL | static _sdef: impl Tr1<As1: Copy> = S1; | ^^^^^^^^^^^^^^^^^^^ -error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in variable binding - --> $DIR/feature-gate-associated_type_bounds.rs:71:12 +error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in variable bindings + --> $DIR/feature-gate-associated_type_bounds.rs:68:12 | LL | let _: impl Tr1<As1: Copy> = S1; | ^^^^^^^^^^^^^^^^^^^ error[E0277]: the trait bound `<<Self as _Tr3>::A as Iterator>::Item: Copy` is not satisfied - --> $DIR/feature-gate-associated_type_bounds.rs:15:28 + --> $DIR/feature-gate-associated_type_bounds.rs:12:28 | LL | type A: Iterator<Item: Copy>; | ^^^^ the trait `Copy` is not implemented for `<<Self as _Tr3>::A as Iterator>::Item` diff --git a/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.rs b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.rs new file mode 100644 index 000000000..83366ea02 --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.rs @@ -0,0 +1,9 @@ +// Check that even though Cell: DispatchFromDyn it remains an invalid self parameter type + +use std::cell::Cell; + +trait Trait{ + fn cell(self: Cell<&Self>); //~ ERROR invalid `self` parameter type: Cell<&Self> +} + +fn main() {} diff --git a/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.stderr b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.stderr new file mode 100644 index 000000000..ce06ce916 --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-cell.stderr @@ -0,0 +1,12 @@ +error[E0307]: invalid `self` parameter type: Cell<&Self> + --> $DIR/feature-gate-dispatch-from-dyn-cell.rs:6:19 + | +LL | fn cell(self: Cell<&Self>); + | ^^^^^^^^^^^ + | + = note: type of `self` must be `Self` or a type that dereferences to it + = help: consider changing to `self`, `&self`, `&mut self`, `self: Box<Self>`, `self: Rc<Self>`, `self: Arc<Self>`, or `self: Pin<P>` (where P is one of the previous types except `Self`) + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0307`. diff --git a/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.rs b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.rs new file mode 100644 index 000000000..23857cbac --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.rs @@ -0,0 +1,35 @@ +// Check that a self parameter type requires a DispatchFromDyn impl to be object safe + +#![feature(arbitrary_self_types, unsize, coerce_unsized)] + +use std::{ + marker::Unsize, + ops::{CoerceUnsized, Deref}, +}; + +struct Ptr<T: ?Sized>(Box<T>); + +impl<T: ?Sized> Deref for Ptr<T> { + type Target = T; + + fn deref(&self) -> &T { + &*self.0 + } +} + +impl<T: Unsize<U> + ?Sized, U: ?Sized> CoerceUnsized<Ptr<U>> for Ptr<T> {} +// Because this impl is missing the coercion below fails. +// impl<T: Unsize<U> + ?Sized, U: ?Sized> DispatchFromDyn<Ptr<U>> for Ptr<T> {} + +trait Trait { + fn ptr(self: Ptr<Self>); +} +impl Trait for i32 { + fn ptr(self: Ptr<Self>) {} +} + +fn main() { + Ptr(Box::new(4)) as Ptr<dyn Trait>; + //~^ ERROR the trait `Trait` cannot be made into an object + //~^^ ERROR the trait `Trait` cannot be made into an object +} diff --git a/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.stderr b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.stderr new file mode 100644 index 000000000..d81eade8e --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-dispatch-from-dyn-missing-impl.stderr @@ -0,0 +1,45 @@ +error[E0038]: the trait `Trait` cannot be made into an object + --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:32:25 + | +LL | fn ptr(self: Ptr<Self>); + | --------- help: consider changing method `ptr`'s `self` parameter to be `&self`: `&Self` +... +LL | Ptr(Box::new(4)) as Ptr<dyn Trait>; + | ^^^^^^^^^^^^^^ `Trait` cannot be made into an object + | +note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety> + --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:25:18 + | +LL | trait Trait { + | ----- this trait cannot be made into an object... +LL | fn ptr(self: Ptr<Self>); + | ^^^^^^^^^ ...because method `ptr`'s `self` parameter cannot be dispatched on + +error[E0038]: the trait `Trait` cannot be made into an object + --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:32:5 + | +LL | fn ptr(self: Ptr<Self>); + | --------- help: consider changing method `ptr`'s `self` parameter to be `&self`: `&Self` +... +LL | Ptr(Box::new(4)) as Ptr<dyn Trait>; + | ^^^^^^^^^^^^^^^^ `Trait` cannot be made into an object + | +note: for a trait to be "object safe" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit <https://doc.rust-lang.org/reference/items/traits.html#object-safety> + --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:25:18 + | +LL | trait Trait { + | ----- this trait cannot be made into an object... +LL | fn ptr(self: Ptr<Self>); + | ^^^^^^^^^ ...because method `ptr`'s `self` parameter cannot be dispatched on +note: required for `Ptr<{integer}>` to implement `CoerceUnsized<Ptr<dyn Trait>>` + --> $DIR/feature-gate-dispatch-from-dyn-missing-impl.rs:20:40 + | +LL | impl<T: Unsize<U> + ?Sized, U: ?Sized> CoerceUnsized<Ptr<U>> for Ptr<T> {} + | --------- ^^^^^^^^^^^^^^^^^^^^^ ^^^^^^ + | | + | unsatisfied trait bound introduced here + = note: required by cast to type `Ptr<dyn Trait>` + +error: aborting due to 2 previous errors + +For more information about this error, try `rustc --explain E0038`. diff --git a/tests/ui/feature-gates/feature-gate-impl_trait_in_fn_trait_return.stderr b/tests/ui/feature-gates/feature-gate-impl_trait_in_fn_trait_return.stderr index 760dcb615..c8c3e13d7 100644 --- a/tests/ui/feature-gates/feature-gate-impl_trait_in_fn_trait_return.stderr +++ b/tests/ui/feature-gates/feature-gate-impl_trait_in_fn_trait_return.stderr @@ -1,4 +1,4 @@ -error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in `Fn` trait return +error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in `Fn` trait return types --> $DIR/feature-gate-impl_trait_in_fn_trait_return.rs:1:24 | LL | fn f() -> impl Fn() -> impl Sized { || () } @@ -7,7 +7,7 @@ LL | fn f() -> impl Fn() -> impl Sized { || () } = note: see issue #99697 <https://github.com/rust-lang/rust/issues/99697> for more information = help: add `#![feature(impl_trait_in_fn_trait_return)]` to the crate attributes to enable -error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in `Fn` trait return +error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in `Fn` trait return types --> $DIR/feature-gate-impl_trait_in_fn_trait_return.rs:3:32 | LL | fn g() -> &'static dyn Fn() -> impl Sized { &|| () } diff --git a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs new file mode 100644 index 000000000..0467dea62 --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.rs @@ -0,0 +1,12 @@ +// check-pass + +#![deny(multiple_supertrait_upcastable)] +//~^ WARNING unknown lint: `multiple_supertrait_upcastable` +//~| WARNING unknown lint: `multiple_supertrait_upcastable` +//~| WARNING unknown lint: `multiple_supertrait_upcastable` +#![warn(multiple_supertrait_upcastable)] +//~^ WARNING unknown lint: `multiple_supertrait_upcastable` +//~| WARNING unknown lint: `multiple_supertrait_upcastable` +//~| WARNING unknown lint: `multiple_supertrait_upcastable` + +fn main() {} diff --git a/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr new file mode 100644 index 000000000..1f725f354 --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-multiple_supertrait_upcastable.stderr @@ -0,0 +1,57 @@ +warning: unknown lint: `multiple_supertrait_upcastable` + --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1 + | +LL | #![deny(multiple_supertrait_upcastable)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: the `multiple_supertrait_upcastable` lint is unstable + = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable + = note: `#[warn(unknown_lints)]` on by default + +warning: unknown lint: `multiple_supertrait_upcastable` + --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1 + | +LL | #![warn(multiple_supertrait_upcastable)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: the `multiple_supertrait_upcastable` lint is unstable + = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable + +warning: unknown lint: `multiple_supertrait_upcastable` + --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1 + | +LL | #![deny(multiple_supertrait_upcastable)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: the `multiple_supertrait_upcastable` lint is unstable + = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable + +warning: unknown lint: `multiple_supertrait_upcastable` + --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1 + | +LL | #![warn(multiple_supertrait_upcastable)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: the `multiple_supertrait_upcastable` lint is unstable + = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable + +warning: unknown lint: `multiple_supertrait_upcastable` + --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:3:1 + | +LL | #![deny(multiple_supertrait_upcastable)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: the `multiple_supertrait_upcastable` lint is unstable + = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable + +warning: unknown lint: `multiple_supertrait_upcastable` + --> $DIR/feature-gate-multiple_supertrait_upcastable.rs:7:1 + | +LL | #![warn(multiple_supertrait_upcastable)] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + | + = note: the `multiple_supertrait_upcastable` lint is unstable + = help: add `#![feature(multiple_supertrait_upcastable)]` to the crate attributes to enable + +warning: 6 warnings emitted + diff --git a/tests/ui/feature-gates/feature-gate-non_lifetime_binders.rs b/tests/ui/feature-gates/feature-gate-non_lifetime_binders.rs new file mode 100644 index 000000000..221e9133f --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-non_lifetime_binders.rs @@ -0,0 +1,4 @@ +fn foo() where for<T> T:, {} +//~^ ERROR only lifetime parameters can be used in this context + +fn main() {} diff --git a/tests/ui/feature-gates/feature-gate-non_lifetime_binders.stderr b/tests/ui/feature-gates/feature-gate-non_lifetime_binders.stderr new file mode 100644 index 000000000..01c8ee30c --- /dev/null +++ b/tests/ui/feature-gates/feature-gate-non_lifetime_binders.stderr @@ -0,0 +1,12 @@ +error[E0658]: only lifetime parameters can be used in this context + --> $DIR/feature-gate-non_lifetime_binders.rs:1:20 + | +LL | fn foo() where for<T> T:, {} + | ^ + | + = note: see issue #108185 <https://github.com/rust-lang/rust/issues/108185> for more information + = help: add `#![feature(non_lifetime_binders)]` to the crate attributes to enable + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0658`. diff --git a/tests/ui/feature-gates/feature-gate-return_position_impl_trait_in_trait.stderr b/tests/ui/feature-gates/feature-gate-return_position_impl_trait_in_trait.stderr index aeabed4a6..0082b6faf 100644 --- a/tests/ui/feature-gates/feature-gate-return_position_impl_trait_in_trait.stderr +++ b/tests/ui/feature-gates/feature-gate-return_position_impl_trait_in_trait.stderr @@ -1,4 +1,4 @@ -error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in trait method return +error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in trait method return types --> $DIR/feature-gate-return_position_impl_trait_in_trait.rs:8:17 | LL | fn bar() -> impl Sized; @@ -7,7 +7,7 @@ LL | fn bar() -> impl Sized; = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable -error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in trait method return +error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in trait method return types --> $DIR/feature-gate-return_position_impl_trait_in_trait.rs:9:21 | LL | fn baz() -> Box<impl std::fmt::Display>; @@ -16,7 +16,7 @@ LL | fn baz() -> Box<impl std::fmt::Display>; = note: see issue #91611 <https://github.com/rust-lang/rust/issues/91611> for more information = help: add `#![feature(return_position_impl_trait_in_trait)]` to the crate attributes to enable -error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in trait method return +error[E0562]: `impl Trait` only allowed in function and inherent method return types, not in trait method return types --> $DIR/feature-gate-return_position_impl_trait_in_trait.rs:15:23 | LL | async fn bar() -> impl Sized; diff --git a/tests/ui/feature-gates/feature-gate-trivial_bounds.stderr b/tests/ui/feature-gates/feature-gate-trivial_bounds.stderr index 1b87ebd9f..d2ad372df 100644 --- a/tests/ui/feature-gates/feature-gate-trivial_bounds.stderr +++ b/tests/ui/feature-gates/feature-gate-trivial_bounds.stderr @@ -95,7 +95,7 @@ LL | fn unsized_local() where Dst<dyn A>: Sized { | ^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time | = help: within `Dst<(dyn A + 'static)>`, the trait `Sized` is not implemented for `(dyn A + 'static)` -note: required because it appears within the type `Dst<(dyn A + 'static)>` +note: required because it appears within the type `Dst<dyn A>` --> $DIR/feature-gate-trivial_bounds.rs:48:8 | LL | struct Dst<X: ?Sized> { |