add regression test for rust-lang#71348

src/test/ui/const-generics/type-dependent/issue-71348.rs

@@ -0,0 +1,35 @@
+// run-pass
+#![feature(const_generics)]
+#![allow(incomplete_features)]
+
+struct Foo {
+    i: i32,
+}
+
+trait Get<'a, const N: &'static str> {
+    type Target: 'a;
+
+    fn get(&'a self) -> &'a Self::Target;
+}
+
+impl Foo {
+    fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<N>>::Target
+    where
+        Self: Get<'a, N>,
+    {
+        self.get()
+    }
+}
+
+impl<'a> Get<'a, "int"> for Foo {
+    type Target = i32;
+
+    fn get(&'a self) -> &'a Self::Target {
+        &self.i
+    }
+}
+
+fn main() {
+    let foo = Foo { i: 123 };
+    assert_eq!(foo.ask::<"int">(), &123);
+}