Should opIndex completely override alias this?

[Steven Schveighoffer]

On Fri, 11 May 2012 13:47:13 -0400, Mehrdad <wfunction at hotmail.com> wrote:

> On Friday, 11 May 2012 at 17:37:11 UTC, Artur Skawina wrote:
>> On 05/11/12 19:22, Mehrdad wrote:
>>> On Friday, 11 May 2012 at 17:19:28 UTC, kenji hara wrote:
>>>> This is expected behavior.
>>>>
>>>> 'alias this' works as proper super type.
>>>>
>>>> struct S { T[] data; alias data this; }
>>>>
>>>> In this code, S behaves as it is derived from T[] .
>>>>
>>>> Following to this view, the definition of opIndex in S overrides (and
>>>> hides) T[]'s opIndex completely.
>>>>
>>>> Kenji Hara
>>>  How do you overcome this, in the case where you don't know the data  
>>> type of 'data' (so you don't know what the overloads might look like,  
>>> maybe because it's a template)?
>>
>> Not quite sure what you mean, but
>>
>>     auto opIndex(A...)(A a) { return data[a]; }
>>
>> artur
>
> What if it's const/pure/@safe/whatever though? Or the parameters have  
> some attributes?
>
> (I guess this is a more general problem than opIndex specifically,  
> though.)

D solves this by automatically adding pure @safe nothrow to a template  
function, wherever it is possible.

However, it doesn't do this for const or immutable.

-Steve