According to 13.8.2 [temp.local] paragraph 5,

A qualified-id is assumed to name a type if

• it is a qualified name in a type-id-only context (see below), or

• it is a decl-specifier of the decl-specifier-seq of a

• simple-declaration or a function-definition in namespace scope,

• member-declaration,

• parameter-declaration in a member-declaration¹⁴⁰, unless that parameter-declaration appears in a default argument,

• ...

This specification would appear to allow an example like:

   template<typename T> struct Y {};
   template<typename T> struct S {
     Y<int(T::type)> m;  // Omitted typename okay because it is in a member-declaration?
  };

The affected parameter-declarations should be only those of the member declarator, not in a member template's template parameter list.

(Note: this issue was spun off from issue 2462 to allow the resolutions to proceed independently.)