return pointer to data declared in function

Question

I know this won\'T work because the variable x gets destroyed when the function returns:

int* myFunction()
{
    int x = 4; return &x;
}

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Answer 1

In C++, you should use new:

int *myFunction()
{
    int blah = 4;
    return new int(blah);
}

And to get rid of it, use delete:

int main(void)
{
    int *myInt = myFunction();
    // do stuff
    delete myInt;
}

Note that I'm invoking the copy constructor for int while using new, so that the value "4" is copied onto the heap memory. The only way to get a pointer to something on the stack reliably is to copy it onto the heap by invoking new properly.

EDIT: As noted in another answer, you will also need to document that the pointer needs to be freed by the caller later on. Otherwise you might have a memory leak.