how can I ensure that a template instantiation is unique?

[Andrea Fontana via Digitalmars-d-learn]

On Thursday, 19 June 2014 at 07:26:12 UTC, Andrea Fontana wrote:
> On Thursday, 19 June 2014 at 05:48:24 UTC, Vlad Levenfeld wrote:
>> I'm instantiating a couple of template structs that conflict 
>> with each other. I'd like them to be unique types, 
>> automatically. So I tried this:
>>
>> template Foo (string unique_id = __FILE__~__LINE__.to!string)
>> {...}
>>
>> but it didn't work. When I use this for templated functions, I 
>> get the file and line number where the function is 
>> instantiated. But in this case, I got the file and line number 
>> where the template was defined.
>>
>> Is there anything I can do to make sure each instantiated type 
>> is unique?
>
> Maybe something like this:
> http://dpaste.dzfl.pl/ce479a2f87f4

Of course Foo2 could be an enum :)