How to detect if a pointer was deleted and securely delete it?

Question

In C++ How to decide or know if a pointer was deleted before??

when i tried to delete a pointer that was previously deleted in another part of the c

Answer 1

I know this thread is old. But if someone else is reading this, he should know about unique_ptr. shared_ptr has indeed an overhead. The counter is stored on the heap. Every time the counter is accessed, there is a risk of a processor cache mismatch. unique_ptr Is more limited but has no overhead in comparison to plain pointers. My suggestion is to prefer unique_ptr over shared_ptr when you do not need reference counting. Another important notice is, that unique_ptr works well with arrays. If i remember correctly this is also true for shared_ptr since C++17.