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Add as_slice() to slice::IterMut and vec::Drain

In bluss/indexmap#88, we found that there was no easy way to implement
`Debug` for our `IterMut` and `Drain` iterators. Those are built on
`slice::IterMut` and `vec::Drain`, which implement `Debug` themselves,
but have no other way to access their data. With a new `as_slice()`
method, we can read the data and customize its presentation.
This commit is contained in:
Josh Stone 2019-03-04 15:12:45 -08:00
parent a9da8fc9c2
commit 538a0963ff
2 changed files with 51 additions and 0 deletions

View file

@ -2468,6 +2468,25 @@ impl<T: fmt::Debug> fmt::Debug for Drain<'_, T> {
}
}
impl<'a, T> Drain<'a, T> {
/// Returns the remaining items of this iterator as a slice.
///
/// # Examples
///
/// ```
/// # #![feature(vec_drain_as_slice)]
/// let mut vec = vec!['a', 'b', 'c'];
/// let mut drain = vec.drain(..);
/// assert_eq!(drain.as_slice(), &['a', 'b', 'c']);
/// let _ = drain.next().unwrap();
/// assert_eq!(drain.as_slice(), &['b', 'c']);
/// ```
#[unstable(feature = "vec_drain_as_slice", reason = "recently added", issue = "0")]
pub fn as_slice(&self) -> &[T] {
self.iter.as_slice()
}
}
#[stable(feature = "drain", since = "1.6.0")]
unsafe impl<T: Sync> Sync for Drain<'_, T> {}
#[stable(feature = "drain", since = "1.6.0")]