D on quora ...

[Ola Fosheim Grøstad]

On Tuesday, 17 October 2017 at 10:05:23 UTC, Atila Neves wrote:
> It's when you have a shared_ptr to an object that has a 
> shared_ptr to an object that has a ... (or unique_ptrs along 
> the way).

Well, yes I've seen some online lectures/tutorials that use it 
for managing graphs and linked lists, but this is overkill in 
most cases. shared_ptr seems most suited for sharing resources 
over threads.

Although I guess you can get that effect if you use it for 
tracking cached objects in a database client or something like 
that.

Sounds more like a problem for people developing frameworks than 
for applications. Frameworks have to make the difficult trade off 
of whether they should roll their own or use a standard 
mechanism. End users often would prefer a standard solution I 
guess.