diff options
Diffstat (limited to 'tests/ui/rfcs/rfc-2027-object-safe-for-dispatch')
3 files changed, 126 insertions, 0 deletions
diff --git a/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/downcast-unsafe-trait-objects.rs b/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/downcast-unsafe-trait-objects.rs new file mode 100644 index 000000000..fa04f4b12 --- /dev/null +++ b/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/downcast-unsafe-trait-objects.rs @@ -0,0 +1,23 @@ +// Check that we if we get ahold of an object unsafe trait +// object with auto traits and lifetimes, we can downcast it +// +// check-pass + +#![feature(object_safe_for_dispatch)] + +trait Trait: Sized {} + +fn downcast_auto(t: &(dyn Trait + Send)) -> &dyn Trait { + t +} + +fn downcast_lifetime<'a, 'b, 't>(t: &'a (dyn Trait + 't)) + -> &'b (dyn Trait + 't) +where + 'a: 'b, + 't: 'a + 'b, +{ + t +} + +fn main() {} diff --git a/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs b/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs new file mode 100644 index 000000000..721890db4 --- /dev/null +++ b/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/manual-self-impl-for-unsafe-obj.rs @@ -0,0 +1,66 @@ +// Check that we can manually implement an object-unsafe trait for its trait object. + +// run-pass + +#![feature(object_safe_for_dispatch)] + +trait Bad { + fn stat() -> char { + 'A' + } + fn virt(&self) -> char { + 'B' + } + fn indirect(&self) -> char { + Self::stat() + } +} + +trait Good { + fn good_virt(&self) -> char { + panic!() + } + fn good_indirect(&self) -> char { + panic!() + } +} + +impl<'a> Bad for dyn Bad + 'a { + fn stat() -> char { + 'C' + } + fn virt(&self) -> char { + 'D' + } +} + +struct Struct {} + +impl Bad for Struct {} + +impl Good for Struct {} + +fn main() { + let s = Struct {}; + + let mut res = String::new(); + + // Directly call static. + res.push(Struct::stat()); // "A" + res.push(<dyn Bad>::stat()); // "AC" + + let good: &dyn Good = &s; + + // These look similar enough... + let bad = unsafe { std::mem::transmute::<&dyn Good, &dyn Bad>(good) }; + + // Call virtual. + res.push(s.virt()); // "ACB" + res.push(bad.virt()); // "ACBD" + + // Indirectly call static. + res.push(s.indirect()); // "ACBDA" + res.push(bad.indirect()); // "ACBDAC" + + assert_eq!(&res, "ACBDAC"); +} diff --git a/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/static-dispatch-unsafe-object.rs b/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/static-dispatch-unsafe-object.rs new file mode 100644 index 000000000..df97d2c13 --- /dev/null +++ b/tests/ui/rfcs/rfc-2027-object-safe-for-dispatch/static-dispatch-unsafe-object.rs @@ -0,0 +1,37 @@ +// Check that we can statically dispatch methods for object +// unsafe trait objects, directly and indirectly +// +// check-pass + +#![feature(object_safe_for_dispatch)] + +trait Statics { + fn plain() {} + fn generic<T>() {} +} + +trait Trait: Sized {} + +impl<'a> Statics for dyn Trait + 'a {} + +fn static_poly<T: Statics + ?Sized>() { + T::plain(); + T::generic::<usize>(); +} + +fn inferred_poly<T: Statics + ?Sized>(t: &T) { + static_poly::<T>(); + T::plain(); + T::generic::<usize>(); +} + +fn call(t: &dyn Trait) { + static_poly::<dyn Trait>(); + inferred_poly(t); +} + +fn main() { + static_poly::<dyn Trait>(); + <dyn Trait>::plain(); + <dyn Trait>::generic::<usize>() +} |