1 files changed, 31 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-17121.rs b/src/test/ui/issues/issue-17121.rs
new file mode 100644
index 000000000..1e7b9f015
--- /dev/null
+++ b/src/test/ui/issues/issue-17121.rs
@@ -0,0 +1,31 @@
+// check-pass
+#![allow(dead_code)]
+// pretty-expanded FIXME #23616
+
+use std::fs::File;
+use std::io::{self, BufReader, Read};
+
+struct Lexer<R: Read>
+{
+    reader: BufReader<R>,
+}
+
+impl<R: Read> Lexer<R>
+{
+    pub fn new_from_reader(r: R) -> Lexer<R>
+    {
+        Lexer{reader: BufReader::new(r)}
+    }
+
+    pub fn new_from_file(p: &str) -> io::Result<Lexer<File>>
+    {
+        Ok(Lexer::new_from_reader(File::open(p)?))
+    }
+
+    pub fn new_from_str<'a>(s: &'a str) -> Lexer<&'a [u8]>
+    {
+        Lexer::new_from_reader(s.as_bytes())
+    }
+}
+
+fn main() {}