Custom hash table key is const, how to call dtors?

[cy via Digitalmars-d-learn]

On Friday, 5 February 2016 at 22:18:50 UTC, Marco Leise wrote:
> But when you remove items from the table you need to call a 
> const/immutable dtor that needs to be written for everything 
> that can be a hash table key.

You need to write destructors for hash keys? How would you use 
string literals as keys then? Could you provide an example 
maybe...?