Make alias parameter optional?

[Robert Rouse]

On Saturday, 25 February 2012 at 22:12:55 UTC, Ali Çehreli wrote:
> On 02/25/2012 01:55 PM, Robert Rouse wrote:
>> On Saturday, 25 February 2012 at 18:54:35 UTC, Trass3r wrote:
>>> void foo(T, T2, alias thing = (){})(T a, T2 b)
>>> {
>>> thing();
>>> }
>>>
>>> void bar(){}
>>>
>>> void main()
>>> {
>>> foo!(int,int,bar)(1,2);
>>> foo(1,2);
>>> }
>>
>> Cool. Didn't know you can do that, but I guess it makes sense 
>> that it
>> would work that way.
>>
>> The only thing I wish for is if I didn't have to explicitly 
>> define what
>> T and T2 were and I could just do
>>
>> foo!(bar)(1,2);
>
> The following works and is news to me. Apparently template 
> parameters with default values need not be at the end of the 
> template parameter list:
>
> void foo(alias thing = (){}, T, T2)(T a, T2 b)
> {
>     thing();
> }
>
> void bar(){}
>
> void main()
> {
>     foo!(bar)(1,2);
> }
>
> Ali

This means that D can simulate Ruby blocks more than I thought. 
That's pretty awesome. I'm loving D more every day.