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Is there any other example of "length" meaning "byte length", or is it just Rust just being confusing? I've never seen this elsewhere.

Offset is ordinarily just a difference of two indices. In a container I don't recall seeing it implicitly refer to byte offset.

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In general in Rust, “length” refers to “count”. If you view strings as being sequences of Unicode scalar values, then it might seem odd that `str::len` counts bytes, but if you view strings as being a subset of byte slices it makes perfect sense that it gives the number of UTF-8 code units (and it is analoguous to, say, how Javascript uses `.length` to return the number of UTF-16 code units). So I think it depends on perspective.

That makes sense, I agree -- seems Rust is on board here too.

It's the usual convention for systems programming languages and has been for decades, e.g. strlen() and std::string.length(). Byte length is also just more useful in many cases.

No, those are counts by definition, and byte lengths only by coincidence. Look at wcslen() and std::wstring::length().

A length could refer to lots of different units - elements, pages, sectors, blocks, N-aligned bytes, kbytes, characters, etc.

Always good to qualify your identifiers with units IMO (or types that reflect units).

> or is it just Rust just being confusing?

It doesn't mean "byte length", so much as "byte" happens to be the element type. Unicode is conventionally represented as UTF-8, so the container can't be directly indexed to yield a character.

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