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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-17 12:02:58 +0000
commit698f8c2f01ea549d77d7dc3338a12e04c11057b9 (patch)
tree173a775858bd501c378080a10dca74132f05bc50 /src/test/ui/coherence/coherence-impl-trait-for-marker-trait-positive.rs
parentInitial commit. (diff)
downloadrustc-698f8c2f01ea549d77d7dc3338a12e04c11057b9.tar.xz
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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/coherence/coherence-impl-trait-for-marker-trait-positive.rs')
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diff --git a/src/test/ui/coherence/coherence-impl-trait-for-marker-trait-positive.rs b/src/test/ui/coherence/coherence-impl-trait-for-marker-trait-positive.rs
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+#![feature(auto_traits)]
+#![feature(negative_impls)]
+
+// Test for issue #56934 - that it is impossible to redundantly
+// implement an auto-trait for a trait object type that contains it.
+
+// Positive impl variant.
+
+auto trait Marker1 {}
+auto trait Marker2 {}
+
+trait Object: Marker1 {}
+
+// A supertrait marker is illegal...
+impl Marker1 for dyn Object + Marker2 { } //~ ERROR E0371
+// ...and also a direct component.
+impl Marker2 for dyn Object + Marker2 { } //~ ERROR E0371
+
+// But implementing a marker if it is not present is OK.
+impl Marker2 for dyn Object {} // OK
+
+// A non-principal trait-object type is orphan even in its crate.
+unsafe impl Send for dyn Marker2 {} //~ ERROR E0117
+
+// And impl'ing a remote marker for a local trait object is forbidden
+// by one of these special orphan-like rules.
+unsafe impl Send for dyn Object {} //~ ERROR E0321
+unsafe impl Send for dyn Object + Marker2 {} //~ ERROR E0321
+
+fn main() { }