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-rw-r--r--src/test/ui/higher-rank-trait-bounds/hrtb-trait-object-paren-notation.rs26
1 files changed, 26 insertions, 0 deletions
diff --git a/src/test/ui/higher-rank-trait-bounds/hrtb-trait-object-paren-notation.rs b/src/test/ui/higher-rank-trait-bounds/hrtb-trait-object-paren-notation.rs
new file mode 100644
index 000000000..d8c726cdd
--- /dev/null
+++ b/src/test/ui/higher-rank-trait-bounds/hrtb-trait-object-paren-notation.rs
@@ -0,0 +1,26 @@
+// run-pass
+// A basic test of using a higher-ranked trait bound.
+
+trait FnLike<A,R> {
+ fn call(&self, arg: A) -> R;
+}
+
+type FnObject<'b> = dyn for<'a> FnLike<(&'a i32,), &'a i32> + 'b;
+
+struct Identity;
+
+impl<'a, T> FnLike<(&'a T,), &'a T> for Identity {
+ fn call(&self, (arg,): (&'a T,)) -> &'a T {
+ arg
+ }
+}
+
+fn call_repeatedly(f: &FnObject) {
+ let x = 3;
+ let y = f.call((&x,));
+ assert_eq!(3, *y);
+}
+
+fn main() {
+ call_repeatedly(&Identity);
+}