Do non-member functions improve encapsulation in D?

[Meta via Digitalmars-d]

On Monday, 21 April 2014 at 16:35:23 UTC, Artur Skawina via 
Digitalmars-d wrote:
> On 04/21/14 14:45, Steven Schveighoffer via Digitalmars-d wrote:
>> Reasons off the top of my head not to make them module 
>> functions:
>
> [...]
>
> Functions, unlike methods, do not work with rvalues.
>
> Ie
>
>    struct S {
>       long[999999] data;
>       auto f() { return data[0]; }
>    }
>
>    auto g(ref S _this) { with (_this) return data[1]; }
>
>    void main() {
>       auto a = S().f();
>       auto b = S().g();
>    }
>
> artur

Shouldn't this be possible if you want to make g a template 
function and use auto ref? Regardless, it doesn't. Probably a 
compiler bug:

   struct S {
      long[999999] data;
      auto f() { return data[0]; }
   }

   //No good
   //auto g(T: S)(auto ref T _this) { with (_this) return data[1]; 
}

   //Doesn't work either
   //auto g()(auto ref S _this) { with (_this) return data[1]; }

   void main() {
      auto a = S().f();
      auto b = S().g();
   }