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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-17 12:02:58 +0000 |
commit | 698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch) | |
tree | 173a775858bd501c378080a10dca74132f05bc50 /src/test/ui/traits/object/with-self-in-projection-output-repeated-supertrait.rs | |
parent | Initial commit. (diff) | |
download | rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz rustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.zip |
Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/test/ui/traits/object/with-self-in-projection-output-repeated-supertrait.rs')
-rw-r--r-- | src/test/ui/traits/object/with-self-in-projection-output-repeated-supertrait.rs | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/src/test/ui/traits/object/with-self-in-projection-output-repeated-supertrait.rs b/src/test/ui/traits/object/with-self-in-projection-output-repeated-supertrait.rs new file mode 100644 index 000000000..39e817168 --- /dev/null +++ b/src/test/ui/traits/object/with-self-in-projection-output-repeated-supertrait.rs @@ -0,0 +1,51 @@ +// build-pass (FIXME(62277): could be check-pass?) + +// FIXME(eddyb) shorten the name so windows doesn't choke on it. +#![crate_name = "trait_test"] + +// Regression test related to #56288. Check that a supertrait projection (of +// `Output`) that references `Self` is ok if there is another occurrence of +// the same supertrait that specifies the projection explicitly, even if +// the projection's associated type is not explicitly specified in the object type. +// +// Note that in order for this to compile, we need the `Self`-referencing projection +// to normalize fairly directly to a concrete type, otherwise the trait resolver +// will hate us. +// +// There is a test in `trait-object-with-self-in-projection-output-bad.rs` that +// having a normalizing, but `Self`-containing projection does not *by itself* +// allow you to avoid writing the projected type (`Output`, in this example) +// explicitly. + +trait ConstI32 { + type Out; +} + +impl<T: ?Sized> ConstI32 for T { + type Out = i32; +} + +trait Base { + type Output; +} + +trait NormalizingHelper: Base<Output=<Self as ConstI32>::Out> + Base<Output=i32> { + type Target; +} + +impl Base for u32 +{ + type Output = i32; +} + +impl NormalizingHelper for u32 +{ + type Target = i32; +} + +fn main() { + // Make sure this works both with and without the associated type + // being specified. + let _x: Box<dyn NormalizingHelper<Target=i32>> = Box::new(2u32); + let _y: Box<dyn NormalizingHelper<Target=i32, Output=i32>> = Box::new(2u32); +} |