LWG3881 Incorrect formatting of container adapters backed by std::string

Author: burblebee

source/containers.tex

@@ -17671,9 +17671,12 @@
   template<class charT, class T, @\libconcept{formattable}@<charT> Container, class... U>
   struct formatter<@\placeholder{adaptor-type}@<T, Container, U...>, charT> {
   private:
-    using @\exposid{maybe-const-adaptor}@ =                                   // \expos
-      @\exposid{fmt-maybe-const}@<@\placeholder{adaptor-type}@<T, Container, U...>, charT>;
-    formatter<Container, charT> @\exposid{underlying_}@;                      // \expos
+    using @\exposid{maybe-const-container}@ =                                             // \expos
+      @\exposid{fmt-maybe-const}@<Container, charT>;
+    using @\exposid{maybe-const-adaptor}@ =                                               // \expos
+      @\exposid{maybe-const}@<is_const_v<@\exposid{maybe-const-container}@>,                          // see \ref{ranges.syn}
+                  @\placeholder{adaptor-type}@<T, Container, U...>>;
+    formatter<ranges::ref_view<@\exposid{maybe-const-container}@>, charT> @\exposid{underlying_}@;    // \expos
 
   public:
     template<class ParseContext>