1 files changed, 55 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-14919.rs b/src/test/ui/issues/issue-14919.rs
new file mode 100644
index 000000000..943615433
--- /dev/null
+++ b/src/test/ui/issues/issue-14919.rs
@@ -0,0 +1,55 @@
+// run-pass
+#![allow(unused_must_use)]
+#![allow(dead_code)]
+// pretty-expanded FIXME #23616
+
+trait Matcher {
+    fn next_match(&mut self) -> Option<(usize, usize)>;
+}
+
+struct CharPredMatcher<'a, 'b> {
+    str: &'a str,
+    pred: Box<dyn FnMut(char) -> bool + 'b>,
+}
+
+impl<'a, 'b> Matcher for CharPredMatcher<'a, 'b> {
+    fn next_match(&mut self) -> Option<(usize, usize)> {
+        None
+    }
+}
+
+trait IntoMatcher<'a, T> {
+    fn into_matcher(self, _: &'a str) -> T;
+}
+
+impl<'a, 'b, F> IntoMatcher<'a, CharPredMatcher<'a, 'b>> for F where F: FnMut(char) -> bool + 'b {
+    fn into_matcher(self, s: &'a str) -> CharPredMatcher<'a, 'b> {
+        CharPredMatcher {
+            str: s,
+            pred: Box::new(self),
+        }
+    }
+}
+
+struct MatchIndices<M> {
+    matcher: M
+}
+
+impl<M: Matcher> Iterator for MatchIndices<M> {
+    type Item = (usize, usize);
+
+    fn next(&mut self) -> Option<(usize, usize)> {
+        self.matcher.next_match()
+    }
+}
+
+fn match_indices<'a, M, T: IntoMatcher<'a, M>>(s: &'a str, from: T) -> MatchIndices<M> {
+    let string_matcher = from.into_matcher(s);
+    MatchIndices { matcher: string_matcher }
+}
+
+fn main() {
+    let s = "abcbdef";
+    match_indices(s, |c: char| c == 'b')
+        .collect::<Vec<_>>();
+}