I think the only reasonable way to interpret this question is "is Rust written by reasonably competent Rust developer spending a reasonable amount of time faster/slower than an equally competent C developer spending the same amount of time".

I don't think a language should count as "fast" if it takes an expert or an inordinate amount of time to get good performance, because most code won't have that.

So on those grounds I would say Rust probably is faster than C, because it makes it much much easier to use multithreading and more optimised libraries. For example a lot of C code uses linked lists because they're easy to write in C, even when a vector would be faster and more appropriate. Multithreading can just be a one line change in Rust.

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oguz-ismail2 16 hours ago | parent | next [-]

So assembly is the slowest language?

	▲	hmry 15 hours ago \| parent \| next [-]
		Depends. If it takes an assembly programmer 8 hours to implement <X>, can an equally proficient Python programmer spending 8 hours to implement <X> create a faster program? Let's say they only need 2 hours to get the <X> to work, and can use the remaining 6 hours for optimizing. Can 6 hours of optimizing a Python program make it faster than the assembly program? The answer isn't obvious, and certainly depends on the specific <X>. I can imagine various <X> where even unlimited time spent optimizing Python code won't produce faster results than the assembly code, unless you drop into C/C++/Zig/Rust/D and write a native Python extension (and of course, at that point you're not comparing against Python, but that native language).
	▲	IshKebab 10 hours ago \| parent \| prev [-]
		Maybe it's best to think of it as an effort-performance graph. For a given amount of effort what performance do you get? Assembly is going to give you pretty great performance generally, but the line only starts when you get to "ridiculous effort"!

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kstrauser 14 hours ago | parent | prev [-]

Or honestly, anything involving a hashmap. Of course you can write those in C, but it’s enough friction that most people won’t for minor things. In Rust, it’s trivial, so people are more likely to use them.