LWG4112 has-arrow should required operator->() to be const-qualified

Author: burblebee

source/ranges.tex

@@ -1634,7 +1634,7 @@
 
 template<class I>
   concept @\defexposconceptnc{has-arrow}@ =                                       // \expos
-    @\libconcept{input_iterator}@<I> && (is_pointer_v<I> || requires(I i) { i.operator->(); });
+    @\libconcept{input_iterator}@<I> && (is_pointer_v<I> || requires(const I i) { i.operator->(); });
 
 template<class T, class U>
   concept @\defexposconceptnc{different-from}@ =                                  // \expos