Comment by pron

All low-level languages (by which I mean languages that offer control over all/most memory allocation) inherently suffer from low abstraction, i.e. there are fewer implementations of a particular interface or, conversely, more changes to the implementation require changes to the interface itself or to its client [1]. This is why even though writing a program in many low-level languages can be not much more expensive than writing the program in a high-level language (one where memory management is entirely or largely automatic), costs accrue in maintenance.

Now, a language like Rust makes some aspects better because it ensures that the maintenance (refactoring) is done correctly -- reducing the risk of mistakes -- but it comes at a cost: you must explain your handling of memory (before and after the refactor) to the compiler (plus, the compiler doesn't understand all patterns). I think it's too soon to empirically compare this cost to the gain in reduced risk and determine when each option is more or less advantageous (and perhaps it is also a matter of personal programmer preference), the fact remains that maintenance of programs in all low-level languages is always more costly than maintenance of programs written in high-level languages because of the low abstraction inherent to all low-level languages.

When writing in a low-level language some may prefer the Rust approach while others may prefer less restrictive ones [2], but people choosing any low-level language should be aware of the added maintenance cost they're invariably signing up for. Sadly, this cost only becomes apparent at later stages of the project.

[1]: Some people claim that memory is just like any other resource (e.g. file descriptors), but this is incorrect. Memory and processing are fundamental to the very nature of abstract algorithms, and differences in how memory is handled change the available range of algorithms. E.g. finite state machines, queue automata, and Turing machines differ only in how memory is handled and accessed. In short -- memory and processing are special resources and are not the same as IO resources.

[2]: I'm personally not a big fan of Rust's approach -- and I particularly dislike C++'s and Rust's "zero-cost abstraction", which is the attempt to make the low abstraction ability invisible in the final code without changing its fundamental aspects -- but I recognise that people's opinions differ on this matter. I also reject the claim that there's no middle ground between Rust and C that offers an intermediate tradeoff between them, i.e. that there is no safety premium to a language that offers some of Rust's safety guarantees but not all of them, such as Zig, or offers better and effective assurance of some properties without a sound guarantee.