Merging upstream version 1.68.2+dfsg1.

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

1 files changed, 65 insertions, 0 deletions

diff --git a/tests/ui/variance/variance-regions-direct.rs b/tests/ui/variance/variance-regions-direct.rs
new file mode 100644
index 000000000..3f34e7655
--- /dev/null
+++ b/tests/ui/variance/variance-regions-direct.rs
@@ -0,0 +1,65 @@
+// Test that we correctly infer variance for region parameters in
+// various self-contained types.
+
+#![feature(rustc_attrs)]
+
+// Regions that just appear in normal spots are contravariant:
+
+#[rustc_variance]
+struct Test2<'a, 'b, 'c> { //~ ERROR [-, -, -]
+    x: &'a isize,
+    y: &'b [isize],
+    c: &'c str
+}
+
+// Those same annotations in function arguments become covariant:
+
+#[rustc_variance]
+struct Test3<'a, 'b, 'c> { //~ ERROR [+, +, +]
+    x: extern "Rust" fn(&'a isize),
+    y: extern "Rust" fn(&'b [isize]),
+    c: extern "Rust" fn(&'c str),
+}
+
+// Mutability induces invariance:
+
+#[rustc_variance]
+struct Test4<'a, 'b:'a> { //~ ERROR [-, o]
+    x: &'a mut &'b isize,
+}
+
+// Mutability induces invariance, even when in a
+// contravariant context:
+
+#[rustc_variance]
+struct Test5<'a, 'b:'a> { //~ ERROR [+, o]
+    x: extern "Rust" fn(&'a mut &'b isize),
+}
+
+// Invariance is a trap from which NO ONE CAN ESCAPE.
+// In other words, even though the `&'b isize` occurs in
+// an argument list (which is contravariant), that
+// argument list occurs in an invariant context.
+
+#[rustc_variance]
+struct Test6<'a, 'b:'a> { //~ ERROR [-, o]
+    x: &'a mut extern "Rust" fn(&'b isize),
+}
+
+// No uses at all is bivariant:
+
+#[rustc_variance]
+struct Test7<'a> { //~ ERROR [*]
+    x: isize
+}
+
+// Try enums too.
+
+#[rustc_variance]
+enum Test8<'a, 'b, 'c:'b> { //~ ERROR [+, -, o]
+    Test8A(extern "Rust" fn(&'a isize)),
+    Test8B(&'b [isize]),
+    Test8C(&'b mut &'c str),
+}
+
+fn main() {}