No trees in the stdlib?

[João Valverde]

João Valverde wrote:
> Paul Rubin wrote:
>> João Valverde <backup95 at netcabo.pt> writes:
>>  
>>> Interesting, thanks. The concept is not difficult to understand but
>>> I'm not sure it would be preferable. A copy operation should have the
>>> same cost as a "snapshot",     
>>
>> You mean a deep-copy?  That is unnecessarily expensive; with a
>> functional structure you can snapshot (or copy) by copying a single
>> pointer.
>>
>>   
>
> Shallow copy...
>
>
Actually I meant whatever that snapshot operation is, minus the 
insertion, if that makes sense.