From 15fd168ee0fe9b4ed24aaaa44cacaa264be4c60b Mon Sep 17 00:00:00 2001
From: Zalathar <Zalathar@users.noreply.github.com>
Date: Tue, 14 Apr 2026 21:06:52 +1000
Subject: [PATCH] Tests for precise-capture through RPIT and TAIT

---
 .../precise-capture-155151.current.stderr     | 12 ++++++++++
 .../impl-trait/rpit/precise-capture-155151.rs | 24 +++++++++++++++++++
 .../precise-capture-155151.current.stderr     | 12 ++++++++++
 .../precise-capture-155151.rs                 | 22 +++++++++++++++++
 4 files changed, 70 insertions(+)
 create mode 100644 tests/ui/impl-trait/rpit/precise-capture-155151.current.stderr
 create mode 100644 tests/ui/impl-trait/rpit/precise-capture-155151.rs
 create mode 100644 tests/ui/type-alias-impl-trait/precise-capture-155151.current.stderr
 create mode 100644 tests/ui/type-alias-impl-trait/precise-capture-155151.rs

diff --git a/tests/ui/impl-trait/rpit/precise-capture-155151.current.stderr b/tests/ui/impl-trait/rpit/precise-capture-155151.current.stderr
new file mode 100644
index 000000000000..39efb77067e7
--- /dev/null
+++ b/tests/ui/impl-trait/rpit/precise-capture-155151.current.stderr
@@ -0,0 +1,12 @@
+error[E0381]: used binding `x` isn't initialized
+  --> $DIR/precise-capture-155151.rs:19:22
+   |
+LL |             let Foo { x } = foo;
+   |                       - binding declared here but left uninitialized
+...
+LL |             let _y = x;
+   |                      ^ `x` used here but it isn't initialized
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0381`.
diff --git a/tests/ui/impl-trait/rpit/precise-capture-155151.rs b/tests/ui/impl-trait/rpit/precise-capture-155151.rs
new file mode 100644
index 000000000000..b01f1098c6c2
--- /dev/null
+++ b/tests/ui/impl-trait/rpit/precise-capture-155151.rs
@@ -0,0 +1,24 @@
+#![crate_type = "rlib"]
+//@ revisions: current next
+//@ edition: 2021
+//@[current] known-bug: #155151
+//@[current] check-fail
+//@[next] compile-flags: -Znext-solver
+//@[next] check-pass
+
+pub fn wut() -> impl Sized {
+    struct Foo { x: u32 }
+
+    if false {
+        // `foo` has an opaque type, but this function knows that it's `Foo`.
+        let foo = wut();
+        let _closure = move || {
+            let Foo { x } = foo;
+            // `x` should have been captured, but under old-solver the compiler
+            // thinks it's uninitialized here.
+            let _y = x;
+        };
+    }
+
+    Foo { x: 7 }
+}
diff --git a/tests/ui/type-alias-impl-trait/precise-capture-155151.current.stderr b/tests/ui/type-alias-impl-trait/precise-capture-155151.current.stderr
new file mode 100644
index 000000000000..972bf142db67
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/precise-capture-155151.current.stderr
@@ -0,0 +1,12 @@
+error[E0381]: used binding `x` isn't initialized
+  --> $DIR/precise-capture-155151.rs:20:18
+   |
+LL |         let Foo { x } = foo;
+   |                   - binding declared here but left uninitialized
+...
+LL |         let _y = x;
+   |                  ^ `x` used here but it isn't initialized
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0381`.
diff --git a/tests/ui/type-alias-impl-trait/precise-capture-155151.rs b/tests/ui/type-alias-impl-trait/precise-capture-155151.rs
new file mode 100644
index 000000000000..b470c9373e93
--- /dev/null
+++ b/tests/ui/type-alias-impl-trait/precise-capture-155151.rs
@@ -0,0 +1,22 @@
+#![feature(type_alias_impl_trait)]
+//@ revisions: current next
+//@ edition: 2021
+//@[current] known-bug: #155151
+//@[current] check-fail
+//@[next] compile-flags: -Znext-solver
+//@[next] check-pass
+
+fn main() {
+    struct Foo { x: u32 }
+
+    type T = impl Sized;
+    // `foo` has an opaque type, but this function knows that it's `Foo`.
+    let foo: T = Foo { x: 7 };
+
+    let _closure = move || {
+        let Foo { x } = foo;
+        // `x` should have been captured, but under old-solver the compiler
+        // thinks it's uninitialized here.
+        let _y = x;
+    };
+}