template mixins vs. string mixins

[Don]

Trass3r wrote:
> In the past template mixins were a neat special usecase of templates. 
> Now with the "mixin template()" syntax they've become a separate thing 
> because you can add special code for handling them, e.g. allowing them 
> to add constructors to classes.
> 
> The question is: what is their right to exist? Is there anything you can 
> do with them you can't with string mixins (or vice versa)?

I've personally never seen a use for template mixins.