If Statement with Declaration

[Dominikus Dittes Scherkl via Digitalmars-d]

On Wednesday, 19 July 2017 at 16:13:28 UTC, Swoorup Joshi wrote:
> On Wednesday, 19 July 2017 at 15:31:08 UTC, ag0aep6g wrote:
>> On 07/19/2017 03:30 PM, sontung wrote:
>>> So I was thinking of some sort of syntax like this:
>>> 
>>>      if(int i = someFunc(); i >= 0)
>>>      {
>>>          // use i
>>>      }
>>> Thoughts on this sort of feature?
>>
>> I'd prefer a new variant of `with`:
>>
>> ----
>> with (int i = someFunc()) if (i >= 0)
>> {
>>     // use i
>> }
>> ----
>>
>> It's slightly more verbose, but the meaning is clearer 
>> (arguable). It extends automatically to other control 
>> structures like `switch`.
>>
>> I wouldn't have this new `with (declaration)` have the magic 
>> lookup rules of the existing `with (expression)`. It would be 
>> a simpler tool that I'd probably use more than the existing 
>> `with`.
>
> I really prefer this over if. This just made sense, just at a 
> glance

Me too.
Would also allow

with(char c = foo()) switch(x)
{
    // use c
}

so no need to switch over the new declared variable, but still 
beeing able to use it there