[vlovich123]

That's my point though. You either have graph structures with loops where the "performance" of the tracing GC is probably irrelevant to the work you're doing OR you have graph ownership without loops. The "without loops" is actually significantly more common and the "loops" case actually has solutions even without going all the way to tracing GC. Also, "performance" has many nuances here. When you say "bolt on GC significantly hinders performance", are you talking about how precisely they can reclaim memory / how quickly after being freed? Or are you talking about the pauses the collector has to make or the atomics it injects throughout to do so in a thread-safe manner?

I suspect the benefits of compaction are wildly overstated because AFAIK compaction isn't cache aware and thus the CPU cache thrashes. By comparison, a language like Rust lets you naturally lay things out in a way that the CPU likes.

> if you have a tracing GC, the simplest way to handle strings is as a heap-allocated immutable array of bytes

But what if I want to mutate the string? Now I have to do a heap allocation and can't do things in-place. Memory can be cheap to move but it can also add up substantially vs an in-place solution.