Memory leak :(

[xoinki]

Hi all,
I have a structure like this..
Struct p
{
int a;
String x;
String y;
};
now,
String is a class.
if i do this..

while()
{
...
.....
Struct p *ptr;
ptr = new ptr;
}

and lets say the loop executes 'n' number of times..
then 'n' number of times delete ptr is executed..
but this is Showing a leak in the String class..
my question whether 'delete' will destroy the string object?

thnx in advance..
xoinki

[weaknessforcats]

A couple of things. This code:

Struct p *ptr;
ptr = new ptr;

won't compile. ptr is declared a pointer. You are allocating a new pointer and "new" returns the address of the newly created pointer. You cannot assign the address of a pointer to a pointer. You need to store it in a pointer declared to cointain the address of another pointer.

Aside from that, deleting a pointer will destroy the object pointed at. Any memory leaks will be caused by faulty destructors.

[Banfa]

Aside from that, deleting a pointer will destroy the object pointed at. Any memory leaks will be caused by faulty destructors.

Assuming that the rest of the code is correctly written. There are many causes of memory leaks faulty destructors being one of them.

[xoinki]

Hi,
Thnx for the reply..
I cheked the destructors its not faulty..
but delete on a structure pointer will not call destructor of a String class i fear..

[Roonie]

destructors are rigged to execute automatically for the most part. there are very few instances where explicitly calling a destructor is appropriate. if your struct is deleted properly, then any members of that struct will also be deleted at that time. (unless of course, youre doing something funky youre not telling us about)

if youre still having problems, try creating an extra {} block to contain the code youre working with . . . the destructors for eveything you declare inside should be called automatically when things fall out of scope at the close of your new block. move all references to your struct inside this new block with as little else as possible and it should help. (if it doesnt fix your problem, at least itll make it more readable for you.)

also, if by off chance youre using an array, you need to use [] with the delete statement:

delete [] yourArray;
 

this tells the compiler to delete the entire array, instead of just the first element (which often causes leaks if youre not looking out.)

[xoinki]

Thnx for the valuable insight sir..
I will try this one out and c