> If one has trouble writing correct cleanup code conventionally (with "goto out" and a single function exit), then allowing them to use defer will only lead to more obscure issues.
I've written countless functions in this style and I don't enjoy it. I think it's better than the other styles of resource cleanup in C, but it's not ideal. In this style, whenever I add a resource to a function, I have to go to the top, add the declaration (with a sentinel value,) then go to the out label, check for the sentinel value and conditionally destroy it. I'd much rather add the declaration, initialization and destruction of the resource all in one place. That would make it much harder to forget the destruction, for one thing.
> And if defer is meant to make code slimmer, it still doesn't belong to C, because it leads to implicit execution and memory/stack allocation.
I don't get the implicit execution thing, and I don't see how it's like that C++ example. The only code that executes is written in the function itself, inside the defer block.
> I've written countless functions in this style and I don't enjoy it. I think it's better than the other styles of resource cleanup in C, but it's not ideal.
I've got almost a couple decades of C behind me, and I agree. The way we handle cleanup at present is not particularly difficult, but it feels irritating. I'd imagine most C programmers agree that the goto based cleanup handlers just happen to be the best we've got, and aren't necessarily ideal.
I've written countless functions in this style and I don't enjoy it. I think it's better than the other styles of resource cleanup in C, but it's not ideal. In this style, whenever I add a resource to a function, I have to go to the top, add the declaration (with a sentinel value,) then go to the out label, check for the sentinel value and conditionally destroy it. I'd much rather add the declaration, initialization and destruction of the resource all in one place. That would make it much harder to forget the destruction, for one thing.
> And if defer is meant to make code slimmer, it still doesn't belong to C, because it leads to implicit execution and memory/stack allocation.
I don't get the implicit execution thing, and I don't see how it's like that C++ example. The only code that executes is written in the function itself, inside the defer block.