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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/auto-traits/typeck-default-trait-impl-precedence.rs
parentInitial commit. (diff)
downloadrustc-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/auto-traits/typeck-default-trait-impl-precedence.rs')
-rw-r--r--src/test/ui/auto-traits/typeck-default-trait-impl-precedence.rs21
1 files changed, 21 insertions, 0 deletions
diff --git a/src/test/ui/auto-traits/typeck-default-trait-impl-precedence.rs b/src/test/ui/auto-traits/typeck-default-trait-impl-precedence.rs
new file mode 100644
index 000000000..2bbe82270
--- /dev/null
+++ b/src/test/ui/auto-traits/typeck-default-trait-impl-precedence.rs
@@ -0,0 +1,21 @@
+// Test that declaring that `&T` is `Defaulted` if `T:Signed` implies
+// that other `&T` is NOT `Defaulted` if `T:Signed` does not hold. In
+// other words, the auto impl only applies if there are no existing
+// impls whose types unify.
+
+#![feature(auto_traits)]
+#![feature(negative_impls)]
+
+auto trait Defaulted { }
+impl<'a,T:Signed> Defaulted for &'a T { }
+impl<'a,T:Signed> Defaulted for &'a mut T { }
+fn is_defaulted<T:Defaulted>() { }
+
+trait Signed { }
+impl Signed for i32 { }
+
+fn main() {
+ is_defaulted::<&'static i32>();
+ is_defaulted::<&'static u32>();
+ //~^ ERROR `u32: Signed` is not satisfied
+}