dg is a delegate and must return a value of the same type as it self. What should "some_type" be to make this work?

some_type delegate() dg;

/*********/
while(   (dg = dg())    !is null){}


(in case you are wondering this would act as a finite state machine)

BCS wrote:
> dg is a delegate and must return a value of the same type as it self. What
> should "some_type" be to make this work?
> 
> some_type delegate() dg;

I don't think this is currently possible in D.


Sean

I think you could use "static if (is(typeof(dg) T))" to do this, more or less.  Not sure, would have to mess with it.

Read more here:
http://www.digitalmars.com/d/expression.html#IsExpression

-[Unknown]


> dg is a delegate and must return a value of the same type as it self. What
> should "some_type" be to make this work?
> 
> some_type delegate() dg;
> 
> /*********/
> while(   (dg = dg())    !is null){}
> 
> 
> (in case you are wondering this would act as a finite state machine)
> 
> 

I did manage a hack around using a struct something like

struct foo
{
	foo delegate() dg;
}
foo dgv;
while(dgv.dg !is null)dgv = dgv.dg();


If function ptrs are used a cast to void* works.

Unknown W. Brackets wrote:
> I think you could use "static if (is(typeof(dg) T))" to do this, more or less.  Not sure, would have to mess with it.
> 
> Read more here:
> http://www.digitalmars.com/d/expression.html#IsExpression
> 
> -[Unknown]
> 
> 
>> dg is a delegate and must return a value of the same type as it self. What
>> should "some_type" be to make this work?
>>
>> some_type delegate() dg;
>>
>> /*********/
>> while(   (dg = dg())    !is null){}
>>
>>
>> (in case you are wondering this would act as a finite state machine)
>>
>>