I tried to use common c++ technique in D:

class Super (alias T)
{
	alias T.Type A; >>> Error: no property 'Type' for type xxx.Sub'

	void test()
	{
		alias T.Type B; >>> ok
	}
}

class Sub : Super !(Sub)
{
	alias int Type;
}

alias A fails to compile although alias B inside scope of function is ok. Is that intended? What is the idea behind that?

Vladimir

Vladimir wrote:
> I tried to use common c++ technique in D:
> 
> class Super (alias T)
> {
> 	alias T.Type A; >>> Error: no property 'Type' for type xxx.Sub'
> 
> 	void test()
> 	{
> 		alias T.Type B; >>> ok
> 	}
> }
> 
> class Sub : Super !(Sub)
> {
> 	alias int Type;
> }
> 
> alias A fails to compile although alias B inside scope of function is ok. Is that intended? What is the idea behind that?

I suspect it must have something to do with 'Sub' not being defined at the point where you're using it as a template parameter.

This compiles:

class Super (T)
{
	alias T.Type A;

	void test()
	{
		alias T.Type B;
	}
}

class Temp
{
	alias int Type;
}

class Sub : Super !(Temp)
{
	alias int Type;
}

void main() {}

Incidently, notice that I'm not using 'alias' in my Super template.  It doesn't seem to be required.

Regan

Regan Heath Wrote:

> Vladimir wrote:
> > I tried to use common c++ technique in D:
> > 
> > class Super (alias T)
> > {
> > 	alias T.Type A; >>> Error: no property 'Type' for type xxx.Sub'
> > 
> > 	void test()
> > 	{
> > 		alias T.Type B; >>> ok
> > 	}
> > }
> > 
> > class Sub : Super !(Sub)
> > {
> > 	alias int Type;
> > }
> > 
> > alias A fails to compile although alias B inside scope of function is ok. Is that intended? What is the idea behind that?
> 
> I suspect it must have something to do with 'Sub' not being defined at the point where you're using it as a template parameter.
> 
> This compiles:
> 
> class Super (T)
> {
> 	alias T.Type A;
> 
> 	void test()
> 	{
> 		alias T.Type B;
> 	}
> }
> 
> class Temp
> {
> 	alias int Type;
> }
> 
> class Sub : Super !(Temp)
> {
> 	alias int Type;
> }
> 
> void main() {}
> 
> Incidently, notice that I'm not using 'alias' in my Super template.  It doesn't seem to be required.
> 
> Regan

Thanks for quick response. Your workarrond is suitable.  I wonder should it be considered as a bug and subject for future fix?

Vladimir wrote:
> Regan Heath Wrote:
> 
>> Vladimir wrote:
>>> I tried to use common c++ technique in D:
>>>
>>> class Super (alias T)
>>> {
>>> 	alias T.Type A; >>> Error: no property 'Type' for type xxx.Sub'
>>>
>>> 	void test()
>>> 	{
>>> 		alias T.Type B; >>> ok
>>> 	}
>>> }
>>>
>>> class Sub : Super !(Sub)
>>> {
>>> 	alias int Type;
>>> }
>>>
>>> alias A fails to compile although alias B inside scope of function is ok. Is that intended? What is the idea behind that?
>> I suspect it must have something to do with 'Sub' not being defined at the point where you're using it as a template parameter.
>>
>> This compiles:
>>
>> class Super (T)
>> {
>> 	alias T.Type A;
>>
>> 	void test()
>> 	{
>> 		alias T.Type B;
>> 	}
>> }
>>
>> class Temp
>> {
>> 	alias int Type;
>> }
>>
>> class Sub : Super !(Temp)
>> {
>> 	alias int Type;
>> }
>>
>> void main() {}
>>
>> Incidently, notice that I'm not using 'alias' in my Super template.  It doesn't seem to be required.
>>
>> Regan
> 
> Thanks for quick response. Your workarrond is suitable.  I wonder should it be considered as a bug and subject for future fix?

I think you should post it to bugzilla, if it's a bug it will get dealt with eventually, if not it will get dealt with eventually.  :)

Regan