diff options
Diffstat (limited to 'src/io/util/fill_buf.rs')
| -rw-r--r-- | src/io/util/fill_buf.rs | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/io/util/fill_buf.rs b/src/io/util/fill_buf.rs index 3655c01..bb07c76 100644 --- a/src/io/util/fill_buf.rs +++ b/src/io/util/fill_buf.rs @@ -40,6 +40,12 @@ impl<'a, R: AsyncBufRead + ?Sized + Unpin> Future for FillBuf<'a, R> { // Safety: This is necessary only due to a limitation in the // borrow checker. Once Rust starts using the polonius borrow // checker, this can be simplified. + // + // The safety of this transmute relies on the fact that the + // value of `reader` is `None` when we return in this branch. + // Otherwise the caller could poll us again after + // completion, and access the mutable reference while the + // returned immutable reference still exists. let slice = std::mem::transmute::<&[u8], &'a [u8]>(slice); Poll::Ready(Ok(slice)) }, |