to auto or not to auto ( in foreach )

[pineapple via Digitalmars-d-learn]

On Sunday, 17 July 2016 at 01:57:21 UTC, pineapple wrote:
> On Saturday, 16 July 2016 at 22:05:49 UTC, ketmar wrote:
>> actually, `foreach (v; rng)` looks like `foreach` is *reusing* 
>> *existing* *variable*. most of the time you can put 
>> `immutable` or something like that there to note that it is 
>> not reusing (purely cosmetical thing), but sometimes you 
>> cannot, and then `auto` is perfect candidate... but it is not 
>> allowed. (sigh)
>
> Chipping in my agreement. foreach(x; y) makes as much syntactic 
> sense as for(x = 0; x < y; x++) where x was not previously 
> defined. One does not expect something that does not look like 
> every other variable definition in the language to be defining 
> a new variable.

Furthermore, if foreach(int x; y) is legal then why isn't 
foreach(auto x; y)?