> void main()
> {
>     StaticThingy.register(new SomeAdapter());
>     StaticThingy.createSome!Dummy();
> }
>
>
> interface FooAdapter
> {
>     FooBundle!(Handle) createSome(Handle)();
> }
>
> private class SomeAdapter : FooAdapter
> {
>     Bundle createSome()
>     {
>         auto w = new Dummy();
>         auto c = new FooDummy();
>         auto b = Bundle(c, w);
>         return b;
>     }
> }
>
> struct StaticThingy
> {
> static:
>     FooBundle!(Handle) createSome(Handle)()
>     {
>         return fooAdapter.createSome!(Handle)();
>     }
>
> // ...


> error: undefined reference to '_D9onlineapp10FooAdapter__T10createSomeTCQBn5DummyZQyMFZSQCd__T9FooBundleTQBiZQp'
> collect2: error: ld returned 1 exit status
> Error: linker exited with status 1


Hey :)

During playing around I came up with code similar to the example above.

As the title says, this code doesn't link.
For the full example please see: https://run.dlang.io/is/mr0u2i

- But should this even compile successfully?
- Does `SomeAdapter` even implement `FooAdapter` correctly?


 ~ Elias

On 12/30/2018 05:05 AM, 0xEAB wrote:

>> interface FooAdapter
>> {
>>     FooBundle!(Handle) createSome(Handle)();
>> }

Function templates cannot be virtual functions. One reason is the compiler cannot know how large the virtual function table should be, and the other one is it's just a template, not the real thing (i.e. not a function).

>> private class SomeAdapter : FooAdapter
>> {
>>     Bundle createSome()

SomeAdapter.createSome is a function unrelated to FooAdapter.createSome. Their only relationship is through "name hiding."

> - Does `SomeAdapter` even implement `FooAdapter` correctly?

Yes because FooAdapter has no virtual function. :p

>   ~ Elias

Ali

On Sunday, 30 December 2018 at 18:55:10 UTC, Ali Çehreli wrote:
> On 12/30/2018 05:05 AM, 0xEAB wrote:
>
> >> interface FooAdapter
> >> {
> >>     FooBundle!(Handle) createSome(Handle)();
> >> }
>
> Function templates cannot be virtual functions. One reason is the compiler cannot know how large the virtual function table should be, and the other one is it's just a template, not the real thing (i.e. not a function).
>
> >> private class SomeAdapter : FooAdapter
> >> {
> >>     Bundle createSome()
>
> SomeAdapter.createSome is a function unrelated to FooAdapter.createSome. Their only relationship is through "name hiding."
>
> > - Does `SomeAdapter` even implement `FooAdapter` correctly?
>
> Yes because FooAdapter has no virtual function. :p
>
> >   ~ Elias
>
> Ali

Thanks for the technical explanation.
  ~ Elias