preparing for const, final, and invariant

[Manuel König]

Walter Bright wrote:
> Manfred Nowak wrote:
>> Walter Bright wrote
>>
>>> Frank Benoit wrote:
>>>> int[] g;
>>>> void foo(in int[] a){
>>>>     g = a.dup;    // allowed?
>>>> }
>>> Yes.
>>
>> The `.dup'ing an array where a cell contains a reference to the array 
>> is allowed too?
>>
>> alias void* T;
>> T[] a;
>> void main(){
>>   T[] g; g.length= 1;
>>   g[0]=&g;
>>   void f( in T[] p){
>>     a= p.dup;
>>   }
>> }
>>
>> That would contradict the given rule.
> 
> I don't understand. What rule is being violated, and how?

I think he is concerning to the scope rule. When 'f' gets called with 
'g' as param, then 'a' has implicitly a reference to 'g', namely in 
a[0]. This would be a violation of the scope rule.

-- Regards
Manuel