1 files changed, 64 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-21058.rs b/src/test/ui/issues/issue-21058.rs
new file mode 100644
index 000000000..6facf0b2d
--- /dev/null
+++ b/src/test/ui/issues/issue-21058.rs
@@ -0,0 +1,64 @@
+// run-pass
+#![allow(dead_code)]
+
+use std::fmt::Debug;
+
+struct NT(str);
+struct DST { a: u32, b: str }
+
+macro_rules! check {
+    (val: $ty_of:expr, $expected:expr) => {
+        assert_eq!(type_name_of_val($ty_of), $expected);
+    };
+    ($ty:ty, $expected:expr) => {
+        assert_eq!(std::any::type_name::<$ty>(), $expected);
+    };
+}
+
+fn main() {
+    // type_name should support unsized types
+    check!([u8], "[u8]");
+    check!(str, "str");
+    check!(dyn Send, "dyn core::marker::Send");
+    check!(NT, "issue_21058::NT");
+    check!(DST, "issue_21058::DST");
+    check!(&i32, "&i32");
+    check!(&'static i32, "&i32");
+    check!((i32, u32), "(i32, u32)");
+    check!(val: foo(), "issue_21058::Foo");
+    check!(val: Foo::new, "issue_21058::Foo::new");
+    check!(val:
+        <Foo as Debug>::fmt,
+        "<issue_21058::Foo as core::fmt::Debug>::fmt"
+    );
+    check!(val: || {}, "issue_21058::main::{{closure}}");
+    bar::<i32>();
+}
+
+trait Trait {
+    type Assoc;
+}
+
+impl Trait for i32 {
+    type Assoc = String;
+}
+
+fn bar<T: Trait>() {
+    check!(T::Assoc, "alloc::string::String");
+    check!(T, "i32");
+}
+
+fn type_name_of_val<T>(_: T) -> &'static str {
+    std::any::type_name::<T>()
+}
+
+#[derive(Debug)]
+struct Foo;
+
+impl Foo {
+    fn new() -> Self { Foo }
+}
+
+fn foo() -> impl Debug {
+    Foo
+}