Can we delete an object passed as by reference?

Question

My code is as below

 fun(int &a)
 {
    delete &a;
 }

 main()
 {
     int *a = new int(10);
     fun(*a);
 }

Can I delete memory assigned in main function and passed as by reference in fun and deleting memory in fun? Is it the right way?

Answer 1

Do not do this:

I guess this is a Mikey-mouse example but in the real world:

1. For a start the int in question may not be created by new - Here is a lot of problems
2. Who owns the object in question. Not the function. Where is the contract?

Please decide who owns an object. Also if the "person" creates it via new should be responsible to delete it.

Check out smart pointers

Answer 2

Short answer: Yes, you can. Do not do it.

References are inmutable, that is, the address (if the compiler implemented the reference as a pointer) is inmutable const. So, if you delete it, the original reference will be pointing to unallocated memory and will crash.

Also, notice that from your code your are passing a reference to the first (and unique) element of the array (if one thinks in pointer as arrays), but fun does not know the size of the array not event that is an array. For example:

 fun(int &a)
 {
    delete &a;
 }

 main()
 {
     int a = 42;
     fun(a);
 }

It will try to delete the address of a reference. Unexpected behaviour.