post qualifier and template constraint limitation, is there a reason ?

[deadalnix via Digitalmars-d]

On Saturday, 17 January 2015 at 10:05:29 UTC, Walter Bright wrote:
> On 1/17/2015 12:33 AM, deadalnix wrote:
>> This is accepted :
>> auto fun(T)(T T) inout if(...) { ... }
>>
>> This is not :
>> auto fun(T)(T T) if(...) inout { ... }
>>
>> Is there a reason ?
>
> There was no known reason to.

Is that possible to make it work then ? Should I open a bug ?