On Sat, Jun 22, 2013 at 4:15 PM, Timon Gehr <timon.g...@gmx.ch> wrote:
> On 06/23/2013 12:55 AM, H. S. Teoh wrote:
>
>> On Sat, Jun 22, 2013 at 10:57:53PM +0200, Jacob Carlborg wrote:
>>
>>> On 2013-06-22 18:40, H. S. Teoh wrote:
>>>
>>> Yeah that one made my eyes glaze over. I still have trouble wrapping my
>>>> brain around the strange syntax of is(), and why its diverse uses have
>>>> been shoehorned into deceptively similar syntax.
>>>>
>>>
>>> Isn't quite a lot of the is-expression features undocumented?
>>>
>> [...]
>>
>>
>> Really? Well, even if so, the cases that *are* currently documented
>> share a lot of syntax, but aren't necessarily related in a way that the
>> syntax might imply. This is very confusing. One example that comes to
>> mind is using is(T _ == U) instead of is(T == U). I'm guessing most
>> people don't even know what the difference is, or why a dummy identifier
>> _ has to be added.
>>
>>
>> T
>>
>>
> It's not a dummy identifier. It introduces _ as an alias to T if used
> inside a static if condition. Otherwise there is no difference.
>
>
> void main(){
> static if(is(int _ == int)){
> _ x;
> }
> static assert(is(typeof(x)==int));
> }
>
> I don't know what the point of this feature is.
>
> There used to be the issue that some forms of is were only available when
> the alias identifier was used. This has been fixed.
>
if that the case can we add it to http://dlang.org/deprecate.html (as
'future' deprecation)?
