pros and cons of smart pointers

Question

I came to know that smart pointer is used for resource management and supports RAII.

But what are the corner cases in which smart pointer doesn\'t seem smart and things

Answer 1

Smart pointers don't help against loops in graph-like structures.

For example, object A holds a smart pointer to object B and object B - back to object A. If you release all pointers to both A and B before disconnection A from B (or B from A) both A and B will hold each other and form a happy memory leak.

Garbage collection could help against that - it could see that both object are unreachable and free them.