DIP69: problem with scope grammar - need a new keyword

[Walter Bright via Digitalmars-d]

On 12/8/2014 2:44 AM, "Marc Schütz" <schuetzm at gmx.net>" wrote:
> On Monday, 8 December 2014 at 10:37:29 UTC, Walter Bright wrote:
>> Another problem with that is:
>>
>>   void func(scope T delegate() dg);
>
> Playing the devil's advocate:
>
>      void func(scope(T delegate()) dg);
>      void func(scope(T) delegate() dg);

Note that:

     void func(ref T delegate() dg);

has the same problem. The only way to make dg return a 'ref T' is to use an alias:

     alias ref T delegate() dg_t;
     void func(dg_t dg);

or put 'ref' as a postfix:

      void func(T delegate() ref dg);

But if the latter solution is used for 'scope', then it interferes with 'scope 
this'.