Tracking issue for io_slice_advance

[Thomasdezeeuw]

This is a tracking issue for IoSlice::{advance, advance_slices} and IoSliceMut::{advance, advance_slices}.

Feature gate: #![feature(io_slice_advance)].

Steps:

• Implement the RFC.
  • Add {IoSlice, IoSliceMut}::advance #62987
  • Rename IoSlice(Mut)::advance to advance_slice and add IoSlice(Mut)::advance #85802
• FCP
• Stabilization PR.

Current API additions:

impl<'a> IoSlice<'a> { // And `IoSliceMut`
    pub fn advance(&mut self, n: usize);
    pub fn advance_slices(bufs: &mut &mut [IoSlice<'a>], n: usize);
}

---

Old issue:

Writing rust-lang/futures-rs#1741 I needed to resort to unsafe code to change the underlying slice in IoSlice (and IoSliceMut). I'm missing a method that can change the underlying slice. @Nemo157 said that I should open an issue.

Current idea would be something like Buf::advance from the bytes crate.

impl IoSlice {
    // Advance the internal cursors of the slice by `n` bytes.
    fn advance(&mut self, n: usize) {
        // ..
    }
}

[Thomasdezeeuw]

Looking for some feedback as to whether this would be accepted.

[Thomasdezeeuw]

Can someone reopen this as the tracking issue for io_slice_advance? I've updated the the first comment, but I'm not sure it's 100% correct.