CODEWITHSUNDEEP
c++heap-memorynew-operatordelete-operatorstack-memory
brainoverflow
brainoverflow

Reputation: 581

Using new operator to statically allocate an object

Of course the next should not be done although it is valid for the compiler. But what is happening when you do?

CClass clss = *new CClass();

On the contrary to the above, the next does compile but gives an assertion error. 

delete &clss;

Does this have something to do with allocating memory on either the stack or the heap?

Upvotes: 1

Views: 150

Answers (2)

Jean-Baptiste Yunès
Jean-Baptiste Yunès

Reputation: 36391

The first line of code is correct, you initialize a statically allocated CClass instance with an another instance dynamically allocated.

The second is obviously wrong as you try to delete an object that has not been dynamically allocated .

The first line produces a memory leak because you dynamically allocate a bunch of memory but never retain its address, so it can never be deallocated (deleted).

Upvotes: 1

TartanLlama
TartanLlama

Reputation: 65600

If you break it down:

new CClass() -> dynamically-allocated instance pointer

CClass clss -> statically-allocated variable

CClass clss = *new CClass(); -> copies the value pointed to by the temporary into clss

&clss -> the address of a statically-allocated variable

delete &clss; -> delete a statically-allocated variable (doesn't make sense)

Upvotes: 2

Related Questions