Perhaps the safety is the tradeoff with the comparative ease of using the language compared to Rust, but I’d love the best of both worlds if it were possible
I am just going to quote what pcwalton said the other day that perhaps answer your question.
>> I’d be much more excited about that promise [memory safety in Rust] if the compiler provided that safety, rather than asking the programmer to do an extraordinary amount of extra work to conform to syntactically enforced safety rules. Put the complexity in the compiler, dudes.
> That exists; it's called garbage collection.
>If you don't want the performance characteristics of garbage collection, something has to give. Either you sacrifice memory safety or you accept a more restrictive paradigm than GC'd languages give you. For some reason, programming language enthusiasts think that if you think really hard, every issue has some solution out there without any drawbacks at all just waiting to be found. But in fact, creating a system that has zero runtime overhead and unlimited aliasing with a mutable heap is as impossible as finding two even numbers whose sum is odd.
I ask because I am obvious blind to other cases - that's what I'm curious about! I generally find the &s to be a net help even without mem safety ... They make it easier to reason about structure, and when things mutate.
This is similar to creating a broadly-used data structure and realizing that some field has to be optional. Option<T> will require you to change everything touching it, and virally spread through all the code that wanted to use that field unconditionally. However, that's not the fault of the Option syntax, it's the fault of semantics of optionality. In languages that don't make this "miserable" at compile time, this problem manifests with a whack-a-mole of NullPointerExceptions at run time.
With experience, I don't get this "oh no, now there's a lifetime popping up everywhere" surprise in Rust any more. Whether something is going to be a temporary view or permanent storage can be known ahead of time, and if it can be both, it can be designed with Cow-like types.
I also got a sense for when using a temporary loan is a premature optimization. All data has to be stored somewhere (you can't have a reference to data that hasn't been stored). Designs that try to be ultra-efficient by allowing only temporary references often force data to be stored in a temporary location first, and then borrowed, which doesn't avoid any allocations, only adds dependencies on external storage. Instead, the design can support moving or collecting data into owned (non-temporary) storage directly. It can then keep it for an arbirary lifetime without lifetime annotations, and hand out temporary references to it whenever needed. The run-time cost can be the same, but the semantics are much easier to work with.