[throwaway894345]

> Yes, Go has fully general GC but very few problem domains have a real need for general GC.

No, no one needs a GC, but many problem domains need productivity, and GC is the most productive way to manage memory to date. As previously mentioned, Rust has made truly impressive strides in improving productivity of borrow-checking, but it still remains quite far behind GC.

[josephg]

Yes, having written a b-tree in rust recently I can confirm this. My child node pointers look like this:

    enum Node<E: EntryTraits, I: TreeIndex<E>> {
        Internal(Pin<Box<NodeInternal<E, I>>>),
        Leaf(Pin<Box<NodeLeaf<E, I>>>),
    }

Yikes. I could probably clean this up a little, but not a lot.

I've been working on this code for months and I still have no idea if my internal b-tree functions should be taking a &mut self, self: Pin<&mut Self> or a NonNull<...> or something else. The compiled code is blazing fast, and being able to control behaviour so clearly with a few parametric type parameters is amazing.

But the process of figuring out the best way to code it up is awful, and it requires all of my attention and capacity. I doubt Rust will ever gain the sort of mainstream usage that javascript & Go have because of how complicated otherwise simple problems can become. Its a great language for the linux kernel and web browsers. But I can't imagine many normal programmers will want to build regular websites and apps in rust.

GC languages are slower, but credit where its due - they make it so much easier to just dive in and spend all your braincells thinking about your problem domain.