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Comment by loeg

1 day ago

Not exactly -- independent subranges of the same range (as would be relevant to something like memcpy/memmove/strcpy). E.g.,

https://godbolt.org/z/YhGajnhEG

It's mentioned later in the same article you shared above.

5 comments

loeg

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oneshtein  13 hours ago 

  fn f() {
    let mut v = vec![1, 2, 3, 4, 5];
    let (header, tail) = v.split_at_mut(1);
    b(&header[0], &mut tail[0]);
  }

  • loeg  5 hours ago

    split_at_mut is just unsafe code (and sibling comment mentioned it hours before you did). The borrow checker doesn't natively understand that.

    • Cyph0n  2 hours ago

      It is safe btw. The difference is that it returns two mutable references vs. one shared ref and one mutable ref. But as they noted, a mutable ref can always be “downgraded” into a shared ref.

Cyph0n  21 hours ago

Gotcha. There is a split_at_mut method that splits a mutable slice reference into two. That doesn’t address the problem you had, but I think that’s best you can do with safe Rust.