Can templated functions be used in interfaces?

[Maxim Fomin]

On Thursday, 11 July 2013 at 12:03:10 UTC, Jakob Ovrum wrote:
> However, in my opinion, it's a bug that you're allowed to 
> declare a function template (when using the shortcut syntax) 
> without defining it, whether in an interface or not. This is a 
> rather natural bug though, due to the nature of function 
> templates:
>
> void a()();
>
> is equivalent of:
>
> template a() { void a(); }
>
> Perhaps it makes sense to allow the declaration without 
> definition when the template and function are explicitly 
> separated (can anyone think of a case where this is useful? 
> Maybe mixin-related?), but when using the former syntax - the 
> function template syntax - I don't think it makes any sense.
>

It is possible in current implementation to split template 
declaration and definition in different modules but in such case 
list of potential template arguments is limited. Disabling this 
option in general would disable D ability to hide template 
implementation (like libraries and external functions). But in 
this particular case I agree that this should be an error like in 
situation with static functions.