1 files changed, 34 insertions, 0 deletions
diff --git a/tests/ui/macros/colorful-write-macros.rs b/tests/ui/macros/colorful-write-macros.rs
new file mode 100644
index 000000000..eb1872cc7
--- /dev/null
+++ b/tests/ui/macros/colorful-write-macros.rs
@@ -0,0 +1,34 @@
+// run-pass
+#![allow(dead_code)]
+use std::io::Write;
+use std::fmt;
+
+struct Foo<'a> {
+    writer: &'a mut (dyn Write+'a),
+    other: &'a str,
+}
+
+struct Bar;
+
+impl fmt::Write for Bar {
+    fn write_str(&mut self, _: &str) -> fmt::Result {
+        Ok(())
+    }
+}
+
+fn borrowing_writer_from_struct_and_formatting_struct_field(foo: Foo) {
+    write!(foo.writer, "{}", foo.other).unwrap();
+}
+
+fn main() {
+    let mut w = Vec::new();
+    write!(&mut w as &mut dyn Write, "").unwrap();
+    write!(&mut w, "").unwrap(); // should coerce
+    println!("ok");
+
+    let mut s = Bar;
+    {
+        use std::fmt::Write;
+        write!(&mut s, "test").unwrap();
+    }
+}