Re: memory leak in the code?

From:

"Andrew Koenig" <ark@acm.org>

Newsgroups:

comp.lang.c++

Date:

Sat, 05 Jan 2008 16:21:12 GMT

Message-ID:

<Y7Ofj.379913$kj1.215132@bgtnsc04-news.ops.worldnet.att.net>

"Erik WikstrFm" <Erik-wikstrom@telia.com> wrote in message
news:zPNfj.2462$R_4.1902@newsb.telia.net...

Yes, but what about if you get a bad_alloc when allocating a? Then you
will try to delete whatever memory that the garbage in a points to. To
prevent this use something like this instead:

try {
int* a = 0;
a = new int[N];
int* b = new int[N];
}
catch (bad_alloc)
{
delete[] a;
}

Well, the idea is right but the implementation is wrong, because a will be
out of scope in the delete statement. Moreover, unless a and b are deleted
inside the try, the code will leak memory if it succeeds, because once a and
b are out of scope, there's no further opportunity to delete the memory.

An alternative:

    int* a = 0;
    try {
        a = new int[N];
        int* b = new int[N];

        // do additional work here

        delete[] b;
        delete[] a;
    } catch (bad_alloc) {
        delete[] a;
    }

I agree with you that smart pointers are the way to go here :-)