[speed_spread]

Java _used_ to give me that "it just works" feeling when I started using it... in 1999. The rich type system makes the biggest difference. In Rust, you can solve a problem by first modelling it through structs and enums and then define operations pertaining to elements of the model. rustc (the compiler) has such a grasp on the implications of a given model that it will most often guide you toward a near-optimal (and safe) solution that ends up working flawlessly the first time you get it running.

[kaba0]

Rust has a cool type system, but I think you give it much more credit, like it doesn’t have dependent types where the implementation can often be filled in literally.

Other than checking mutability and nullness, I really don’t think that Rust would be that much ahead compared to even an “older” language like Java.

Also, java now has ADTs so “exhaustive checks” are available there as well.

[Measter]

I can't compare with Java, but I can for C#. With Rust I find that I have much more confidence that I understand what the code is doing primarily due to the borrow checker and how Rust enforces unique vs shared access vs ownership. Just by knowing the types involved, I know exactly what a function could potentially do to what I pass in just by looking at the call site.

In C#, I can't tell at the call site whether a function could mutate what I pass in; not without looking at the implementation of the function and anything it passes that object to. With Rust, how it's passed in completely informs me about this. If it's passed by shared reference, it can't mutate. If it's passed by unique reference, it might mutate. If it's passed by ownership, then I can't access the instance any more anyway, so it's not my problem.