Persistent list

[Timon Gehr via Digitalmars-d]

On 11/16/2015 07:37 PM, Andrei Alexandrescu wrote:
> On 11/16/2015 12:51 PM, Steven Schveighoffer wrote:
>>      List tail() const
>
> I'd like tail to be qualifier-idempotent, i.e. return const for const
> and non-const for non-const. -- Andrei

"Qualifier-idempotent" would rather mean that taking the tail once 
results in the same qualifier as taking it twice.

https://en.wikipedia.org/wiki/Idempotence