Merge pull request #1079 from Patrick-Poitras/add-issue-91603

Add issue #91603

Author: Alexendoo

ices/91603.rs

@@ -0,0 +1,13 @@
+pub trait WorldQuery {
+    type Fetch: for<'world> Fetch<'world>;
+}
+
+fn main() {}
+
+pub trait Fetch<'world> {
+    type Item;
+}
+
+pub type QueryItem<'w, Q> = <<Q as WorldQuery>::Fetch as Fetch<'w>>::Item;
+
+fn first_child() -> impl FnOnce(&u32) -> QueryItem<u32> {}