The alternatives with the potential to be as fast (C, C++, D, zig) are more complex in this regard because they make memory safety and lifetime tracking something that you have to keep track of in your head. Rust's biggest win is removing that mental overhead while allowing you to achieve the same performance as those other languages.

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LAC-Tech 2 hours ago | parent [-]

Rust also hides allocation, and both the standard library and community best practices encourage many smaller allocations, which makes it much harder to reason about performance characteristics of your code.

So what you say is definitely true if you do an allocation heavy, heap fragmenting, RAII style of programming. Which is the context Rust was born in, right? A kind of C++ app dev context where that was (is?) the prevailing meta.

You're also completely glossing over the incredible complexity you get in all thee weird intersection of rust features. And there are a LOT of features. Reasoning about those are not free from a mental overhead stand point.

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nicoburns an hour ago | parent [-]

> Rust also hides allocation.

Does it? In Rust you allocate by calling a function. That's exactly the same as C. Are there any langauges that don't allow you to hide allocation behind a function call?

> So what you say is definitely true if you do an allocation heavy, heap fragmenting, RAII style of programming.

I don't think Rust encourages lots of small allocations. Most of the Rust code I work with does a lot of arena allocation (using crates like https://github.com/orlp/slotmap) and reusing of allocations. And for that matter a lot of stack allocation avoiding the heap entirely. And it's borrowing system is fantastic for working with shared pointers to data without having to worry that something might accidentally overwrite it.

> You're also completely glossing over the incredible complexity you get in all thee weird intersection of rust features.

I don't really buy that Rust is complex. More complex than C I suppose (but C just pushes all the complexity into making you write 5x more application code), but closer to something like Java than something like C++.

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int_19h an hour ago | parent [-]

It's significantly more complex than Java due to the borrow checker and lifetimes in generics.

	▲	koakuma-chan 21 minutes ago \| parent [-]
		I don't think Rust is all that complex. On the other hand Java has many obscure features like serialVersionUID. For that matter, even fucking JavaScript is more complex than Rust with its var vs let, == vs ===, how, e.g., an empty array is false, parsing Date, how to make a "deep copy," etc, and TypeScript's type system can run Doom.