1 files changed, 20 insertions, 0 deletions
diff --git a/tests/ui/for/issue-20605.rs b/tests/ui/for/issue-20605.rs
new file mode 100644
index 000000000..50d4c3fdd
--- /dev/null
+++ b/tests/ui/for/issue-20605.rs
@@ -0,0 +1,20 @@
+// revisions: current next
+//[next] compile-flags: -Ztrait-solver=next
+
+fn changer<'a>(mut things: Box<dyn Iterator<Item=&'a mut u8>>) {
+    for item in *things { *item = 0 }
+    //[current]~^ ERROR the size for values of type
+    //[next]~^^ ERROR the trait bound `dyn Iterator<Item = &'a mut u8>: IntoIterator` is not satisfied
+    //[next]~| ERROR the size for values of type `<dyn Iterator<Item = &'a mut u8> as IntoIterator>::IntoIter` cannot be known at compilation time
+    //[next]~| ERROR the type `<dyn Iterator<Item = &'a mut u8> as IntoIterator>::IntoIter` is not well-formed
+    //[next]~| ERROR `<dyn Iterator<Item = &'a mut u8> as IntoIterator>::IntoIter` is not an iterator
+    //[next]~| ERROR the type `&mut <dyn Iterator<Item = &'a mut u8> as IntoIterator>::IntoIter` is not well-formed
+    //[next]~| ERROR the size for values of type `<<dyn Iterator<Item = &'a mut u8> as IntoIterator>::IntoIter as Iterator>::Item` cannot be known at compilation time
+    //[next]~| ERROR the type `Option<<<dyn Iterator<Item = &'a mut u8> as IntoIterator>::IntoIter as Iterator>::Item>` is not well-formed
+    //[next]~| ERROR the size for values of type `<<dyn Iterator<Item = &'a mut u8> as IntoIterator>::IntoIter as Iterator>::Item` cannot be known at compilation time
+    //[next]~| ERROR type `<<dyn Iterator<Item = &'a mut u8> as IntoIterator>::IntoIter as Iterator>::Item` cannot be dereferenced
+    // FIXME(-Ztrait-solver=next): these error messages are horrible and have to be
+    // improved before we stabilize the new solver.
+}
+
+fn main() {}