Why can I not call my class's constructor from an instance of that class in C++?

Question

When can an object of a class call the destructor of that class, as if it\'s a regular function? Why can\'t it call the constructor of the same class, as one of its regular

Answer 1

A destructor must be called on an existing instance of a class - destructing the instance is what it does. A constructor creates a brand new instance of a class, so calling on an existing instance makes no sense.

This is similar to the way new and delete work:

int * p = new int;    // call to new needs no existing instance
delete p;             // call to delete requires existing instance

And note in your code, the object would be destroyed twice, once explicitly, and once implicitly at the end of its enclosing scope. You typically only explicitly call a destructor if you are doing something unusual, probably involving the use of placement new.