use std::io::{IoSlice, IoSliceMut};
pub trait AsIoSlices<'arena>: 'arena {
unsafe fn as_io_slices(&self) -> &[IoSlice<'_>];
}
pub trait AsIoSlicesMut<'arena>: 'arena {
unsafe fn as_io_slices_mut(&mut self) -> &mut [IoSliceMut<'arena>];
fn set_init(&mut self, len: usize);
}