Is missing delete undefined behaviour?

Question

When I allocate memory and do not call delete, is this undefined behaviour?

Example:

int main(int argc, char** argv) {
    int* a = new int[1];
    // next code only to prevent optimization (hopefully)
    *a = argc; std::cout << *a << std::endl;
    // no delete
    return 0;
}

(Let us assume the new is not optimized out).

No, this is defined behavior: a memory leak. Since your program exits right afterwards, the OS will still reclaim all its memory, though. — Frédéric Hamidi, Jun 10 '14 at 08:44
@juanchopanza: Thanks for the link, did not found it be search... — Danvil, Jun 10 '14 at 09:05

score 0 · Answer 1 · answered Jun 10 '14 at 08:44

0

It's not undefined behaviour; it's a memory leak.

Of course leaks "exist" only as long as the process is still running; in this case the process exits (and the concept of leak becomes moot) immediately afterwards.

answered Jun 10 '14 at 08:44

Jon

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I would say it is undefined behaviour, since the program relies on side-effects of the call to the destructor (i.e. the program could run out of memory if it isn't called.) But it isn't crystal clear. – juanchopanza Jun 10 '14 at 08:57
Who downvoted this and why? I would like to understand if a statement is wrong or something? (upvoted) – Jun 10 '14 at 08:57
@juanchopanza: Sorry, what? The program clearly does not rely on any side effects, there is no destructor to begin with because `int[]` is not a class type, and running out of memory is not undefined behavior anyway. – Jon Jun 10 '14 at 09:01
Sorry, I still had [a similar, recent question](http://stackoverflow.com/questions/24136120/what-is-wrong-with-using-arrays-dynamically-allocated-in-c) in my head, where the array was one of `std::string`. – juanchopanza Jun 10 '14 at 09:03

Is missing delete undefined behaviour?

1 Answers1