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Comment by i4k | Hacker News Reader

On the other hand, is more clear where things are released. When over relying on destructors, often it becomes trick to known when it happens and in which order. This kind of trade off is important to take into consideration depending on the project.

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Maybe I'm too used to C++ and Rust but I don't find it tricky at all. Its very clearly defined when a destructor (or fn drop) is called as well as the order (inverse allocation order).

What I would like to see would be some way of forcing users to manually call the dtor/drop. So when I use a type like that I have to manually decide when it gets destroyed, and have actual compile checks that I do destroy the object in every code path.

I will admit that I really miss the "value semantics" thing that RAII gives you when working in Zig. A good example is collections, like hash tables or whatever: ownership is super clear in C++/Rust. When the hash tables goes away, all the contained values goes away, because the table owns its contents. When you assign a key/value, you don't have to consider what happens to the old key/value (if there was one), RAII just takes care of it. A type that manages a resource has value semantics just like "primitive" types, you don't have to worry.

Not so in Zig: whenever you deal with collections where either the keys or values manages a resource (i.e. does not have value semantics), you have to be incredibly careful, because you have to consider lifetimes of the HashMap and the keys/values separately. A function like HashMap.put is sort of terrifying for this reason, very easy to create a memory leak.

I get why Zig does it though, and I don't think adding C++/Rust style value semantics into the language is a good idea. But it certainly sometimes makes it more challenging to work in.

Among systems languages, I've mostly used C and Zig. I don't think dtor order is tricky so much as I think that defaulting to fine-grained automatic resource management including running a lot of destructors causes programs that use this default to pay large costs at runtime :(

I think the latter problem is impossible, you end up needing RAII or a type-level lifetime system that can't express a lot of correct programs. I would like something that prevents "accidentally didn't deinit" in simple cases, but it probably wouldn't prevent "accidentally didn't call reset on your FixedBufferAllocator" because the tooling doesn't know about your request lifecycle.

You want a code analyzer on top of a language like zig. I think people think it's hard because it would really be hard for C. Probably would be MUCH easier in zig.

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