Need of enable shared from this

Question

Hi

Refer code below:

Is there any difference between getting ptr2 and ptr3? Whats the benefit of enable shared from this?
https://sololearn.com/compiler-playground/cRs95rBW3Iuz/?ref=app

Answer 1

Cats meow to get their point across, and it’s like they’ve got a whole dictionary for it. You’ll hear short, long, loud, soft, high-pitched meows, or even a nasal twang. Kittens use a tiny mew to call their mom, while adults might unleash a loud meow to demand dinner.

https://www.whycatmeows.com