Adding upstream version 1.64.0+dfsg1.upstream/1.64.0+dfsg1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 31 insertions, 0 deletions

diff --git a/src/test/ui/never_type/never-value-fallback-issue-66757.rs b/src/test/ui/never_type/never-value-fallback-issue-66757.rs
new file mode 100644
index 000000000..fc6fe6eb5
--- /dev/null
+++ b/src/test/ui/never_type/never-value-fallback-issue-66757.rs
@@ -0,0 +1,31 @@
+// Regression test for #66757
+//
+// Test than when you have a `!` value (e.g., the local variable
+// never) and an uninferred variable (here the argument to `From`) it
+// doesn't fallback to `()` but rather `!`.
+//
+// revisions: nofallback fallback
+//[fallback] run-pass
+//[nofallback] check-fail
+
+#![feature(never_type)]
+
+#![cfg_attr(fallback, feature(never_type_fallback))]
+
+struct E;
+
+impl From<!> for E {
+    fn from(_: !) -> E {
+        E
+    }
+}
+
+#[allow(unreachable_code)]
+#[allow(dead_code)]
+#[allow(unused_must_use)]
+fn foo(never: !) {
+    <E as From<!>>::from(never);  // Ok
+    <E as From<_>>::from(never);  //[nofallback]~ ERROR trait bound `E: From<()>` is not satisfied
+}
+
+fn main() { }