1 files changed, 40 insertions, 0 deletions
diff --git a/src/test/ui/nll/user-annotations/issue-57731-ascibed-coupled-types.rs b/src/test/ui/nll/user-annotations/issue-57731-ascibed-coupled-types.rs
new file mode 100644
index 000000000..9b3ec702c
--- /dev/null
+++ b/src/test/ui/nll/user-annotations/issue-57731-ascibed-coupled-types.rs
@@ -0,0 +1,40 @@
+// Check that repeated type variables are correctly handled
+
+#![allow(unused)]
+#![feature(type_ascription)]
+
+type PairUncoupled<'a, 'b, T> = (&'a T, &'b T);
+type PairCoupledTypes<T> = (T, T);
+type PairCoupledRegions<'a, T> = (&'a T, &'a T);
+
+fn uncoupled_wilds_rhs<'a>(_x: &'a u32, s: &'static u32) -> &'static u32 {
+    let ((y, _z),) = ((s, _x),): (PairUncoupled<_>,);
+    y // OK
+}
+
+fn coupled_wilds_rhs<'a>(_x: &'a u32, s: &'static u32) -> &'static u32 {
+    let ((y, _z),) = ((s, _x),): (PairCoupledTypes<_>,);
+    y //~ ERROR lifetime may not live long enough
+}
+
+fn coupled_regions_rhs<'a>(_x: &'a u32, s: &'static u32) -> &'static u32 {
+    let ((y, _z),) = ((s, _x),): (PairCoupledRegions<_>,);
+    y //~ ERROR lifetime may not live long enough
+}
+
+fn cast_uncoupled_wilds_rhs<'a>(_x: &'a u32, s: &'static u32) -> &'static u32 {
+    let ((y, _z),) = ((s, _x),) as (PairUncoupled<_>,);
+    y // OK
+}
+
+fn cast_coupled_wilds_rhs<'a>(_x: &'a u32, s: &'static u32) -> &'static u32 {
+    let ((y, _z),) = ((s, _x),) as (PairCoupledTypes<_>,);
+    y //~ ERROR lifetime may not live long enough
+}
+
+fn cast_coupled_regions_rhs<'a>(_x: &'a u32, s: &'static u32) -> &'static u32 {
+    let ((y, _z),) = ((s, _x),) as (PairCoupledRegions<_>,);
+    y //~ ERROR lifetime may not live long enough
+}
+
+fn main() {}