From 40e76c157548442fce755ec9cc2274aef11454ba Mon Sep 17 00:00:00 2001
From: mejrs <59372212+mejrs@users.noreply.github.com>
Date: Tue, 1 Apr 2025 02:47:12 +0200
Subject: [PATCH] Test that `Self` properly works in filters

---
 .../ui/on-unimplemented/use_self_no_underscore.rs | 14 ++++++++++++++
 .../use_self_no_underscore.stderr                 | 15 +++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100644 tests/ui/on-unimplemented/use_self_no_underscore.rs
 create mode 100644 tests/ui/on-unimplemented/use_self_no_underscore.stderr

diff --git a/tests/ui/on-unimplemented/use_self_no_underscore.rs b/tests/ui/on-unimplemented/use_self_no_underscore.rs
new file mode 100644
index 000000000000..045ef1a5d3ff
--- /dev/null
+++ b/tests/ui/on-unimplemented/use_self_no_underscore.rs
@@ -0,0 +1,14 @@
+#![feature(rustc_attrs)]
+
+#[rustc_on_unimplemented(on(
+    all(A = "{integer}", any(Self = "[{integral}; _]",)),
+    message = "an array of type `{Self}` cannot be built directly from an iterator",
+))]
+pub trait FromIterator<A>: Sized {
+    fn from_iter<T: IntoIterator<Item = A>>(iter: T) -> Self;
+}
+fn main() {
+    let iter = 0..42_8;
+    let x: [u8; 8] = FromIterator::from_iter(iter);
+    //~^ ERROR an array of type `[u8; 8]` cannot be built directly from an iterator
+}
diff --git a/tests/ui/on-unimplemented/use_self_no_underscore.stderr b/tests/ui/on-unimplemented/use_self_no_underscore.stderr
new file mode 100644
index 000000000000..d01aee3485f4
--- /dev/null
+++ b/tests/ui/on-unimplemented/use_self_no_underscore.stderr
@@ -0,0 +1,15 @@
+error[E0277]: an array of type `[u8; 8]` cannot be built directly from an iterator
+  --> $DIR/use_self_no_underscore.rs:12:22
+   |
+LL |     let x: [u8; 8] = FromIterator::from_iter(iter);
+   |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `FromIterator<{integer}>` is not implemented for `[u8; 8]`
+   |
+help: this trait has no implementations, consider adding one
+  --> $DIR/use_self_no_underscore.rs:7:1
+   |
+LL | pub trait FromIterator<A>: Sized {
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.