From 698f8c2f01ea549d77d7dc3338a12e04c11057b9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Wed, 17 Apr 2024 14:02:58 +0200
Subject: Adding upstream version 1.64.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 .../ty-outlives/projection-one-region-closure.rs   | 83 ++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 src/test/ui/nll/ty-outlives/projection-one-region-closure.rs

(limited to 'src/test/ui/nll/ty-outlives/projection-one-region-closure.rs')

diff --git a/src/test/ui/nll/ty-outlives/projection-one-region-closure.rs b/src/test/ui/nll/ty-outlives/projection-one-region-closure.rs
new file mode 100644
index 000000000..af361e990
--- /dev/null
+++ b/src/test/ui/nll/ty-outlives/projection-one-region-closure.rs
@@ -0,0 +1,83 @@
+// Test cases where we constrain `<T as Anything<'b>>::AssocType` to
+// outlive `'a` and there are no bounds in the trait definition of
+// `Anything`. This means that the constraint can only be satisfied in two
+// ways:
+//
+// - by ensuring that `T: 'a` and `'b: 'a`, or
+// - by something in the where clauses.
+//
+// As of this writing, the where clause option does not work because
+// of limitations in our region inferencing system (this is true both
+// with and without NLL). See `projection_outlives`.
+//
+// Ensuring that both `T: 'a` and `'b: 'a` holds does work (`elements_outlive`).
+
+// compile-flags:-Zverbose
+
+#![allow(warnings)]
+#![feature(rustc_attrs)]
+
+use std::cell::Cell;
+
+trait Anything<'a> {
+    type AssocType;
+}
+
+fn with_signature<'a, T, F>(cell: Cell<&'a ()>, t: T, op: F)
+where
+    F: FnOnce(Cell<&'a ()>, T),
+{
+    op(cell, t)
+}
+
+fn require<'a, 'b, T>(_cell: Cell<&'a ()>, _t: T)
+where
+    T: Anything<'b>,
+    T::AssocType: 'a,
+{
+}
+
+#[rustc_regions]
+fn no_relationships_late<'a, 'b, T>(cell: Cell<&'a ()>, t: T)
+where
+    T: Anything<'b>,
+{
+    with_signature(cell, t, |cell, t| require(cell, t));
+    //~^ ERROR the parameter type `T` may not live long enough
+    //~| ERROR
+}
+
+#[rustc_regions]
+fn no_relationships_early<'a, 'b, T>(cell: Cell<&'a ()>, t: T)
+where
+    T: Anything<'b>,
+    'a: 'a,
+{
+    with_signature(cell, t, |cell, t| require(cell, t));
+    //~^ ERROR the parameter type `T` may not live long enough
+    //~| ERROR
+}
+
+#[rustc_regions]
+fn projection_outlives<'a, 'b, T>(cell: Cell<&'a ()>, t: T)
+where
+    T: Anything<'b>,
+    T::AssocType: 'a,
+{
+    // We are projecting `<T as Anything<'b>>::AssocType`, and we know
+    // that this outlives `'a` because of the where-clause.
+
+    with_signature(cell, t, |cell, t| require(cell, t));
+}
+
+#[rustc_regions]
+fn elements_outlive<'a, 'b, T>(cell: Cell<&'a ()>, t: T)
+where
+    T: Anything<'b>,
+    T: 'a,
+    'b: 'a,
+{
+    with_signature(cell, t, |cell, t| require(cell, t));
+}
+
+fn main() {}
-- 
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