#[doc(hidden)]
#[unstable(issue = "none", feature = "std_internals")]
+#[rustc_unsafe_specialization_marker]
+pub trait NonDrop {}
+
// T: Copy as approximation for !Drop since get_unchecked does not advance self.ptr
// and thus we can't implement drop-handling
-//
+#[unstable(issue = "none", feature = "std_internals")]
+impl<T: Copy> NonDrop for T {}
+
+#[doc(hidden)]
+#[unstable(issue = "none", feature = "std_internals")]
// TrustedRandomAccess (without NoCoerce) must not be implemented because
-// subtypes/supertypes of `T` might not be `Copy`
+// subtypes/supertypes of `T` might not be `NonDrop`
unsafe impl<T, A: Allocator> TrustedRandomAccessNoCoerce for IntoIter<T, A>
where
- T: Copy,
+ T: NonDrop,
{
const MAY_HAVE_SIDE_EFFECT: bool = false;
}
/// Specialization marker for collecting an iterator pipeline into a Vec while reusing the
/// source allocation, i.e. executing the pipeline in place.
-///
-/// The SourceIter parent trait is necessary for the specializing function to access the allocation
-/// which is to be reused. But it is not sufficient for the specialization to be valid. See
-/// additional bounds on the impl.
#[rustc_unsafe_specialization_marker]
-pub(super) trait SourceIterMarker: SourceIter<Source: AsIntoIter> {}
+pub(super) trait InPlaceIterableMarker {}
-// The std-internal SourceIter/InPlaceIterable traits are only implemented by chains of
-// Adapter<Adapter<Adapter<IntoIter>>> (all owned by core/std). Additional bounds
-// on the adapter implementations (beyond `impl<I: Trait> Trait for Adapter<I>`) only depend on other
-// traits already marked as specialization traits (Copy, TrustedRandomAccess, FusedIterator).
-// I.e. the marker does not depend on lifetimes of user-supplied types. Modulo the Copy hole, which
-// several other specializations already depend on.
-impl<T> SourceIterMarker for T where T: SourceIter<Source: AsIntoIter> + InPlaceIterable {}
+impl<T> InPlaceIterableMarker for T where T: InPlaceIterable {}
impl<T, I> SpecFromIter<T, I> for Vec<T>
where
- I: Iterator<Item = T> + SourceIterMarker,
+ I: Iterator<Item = T> + SourceIter<Source: AsIntoIter> + InPlaceIterableMarker,
{
default fn from_iter(mut iterator: I) -> Self {
// Additional requirements which cannot expressed via trait bounds. We rely on const eval
unsafe impl<I> TrustedLen for Enumerate<I> where I: TrustedLen {}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, I: Iterator> SourceIter for Enumerate<I>
+unsafe impl<I> SourceIter for Enumerate<I>
where
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
impl<I: FusedIterator, P> FusedIterator for Filter<I, P> where P: FnMut(&I::Item) -> bool {}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, P, I: Iterator> SourceIter for Filter<I, P>
+unsafe impl<P, I> SourceIter for Filter<I, P>
where
- P: FnMut(&I::Item) -> bool,
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
impl<B, I: FusedIterator, F> FusedIterator for FilterMap<I, F> where F: FnMut(I::Item) -> Option<B> {}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, B, I: Iterator, F> SourceIter for FilterMap<I, F>
+unsafe impl<I, F> SourceIter for FilterMap<I, F>
where
- F: FnMut(I::Item) -> Option<B>,
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
impl<I: FusedIterator, F> FusedIterator for Inspect<I, F> where F: FnMut(&I::Item) {}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, I: Iterator, F> SourceIter for Inspect<I, F>
+unsafe impl<I, F> SourceIter for Inspect<I, F>
where
- F: FnMut(&I::Item),
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, B, I: Iterator, F> SourceIter for Map<I, F>
+unsafe impl<I, F> SourceIter for Map<I, F>
where
- F: FnMut(I::Item) -> B,
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, B, I: Iterator, P> SourceIter for MapWhile<I, P>
+unsafe impl<I, P> SourceIter for MapWhile<I, P>
where
- P: FnMut(I::Item) -> Option<B>,
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
/// [`as_inner`]: SourceIter::as_inner
#[unstable(issue = "none", feature = "inplace_iteration")]
#[doc(hidden)]
+#[rustc_specialization_trait]
pub unsafe trait SourceIter {
/// A source stage in an iterator pipeline.
- type Source: Iterator;
+ type Source;
/// Retrieve the source of an iterator pipeline.
///
}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, I, E> SourceIter for ResultShunt<'_, I, E>
+unsafe impl<I, E> SourceIter for ResultShunt<'_, I, E>
where
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut Self::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
unsafe impl<I> TrustedLen for Peekable<I> where I: TrustedLen {}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, I: Iterator> SourceIter for Peekable<I>
+unsafe impl<I: Iterator> SourceIter for Peekable<I>
where
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<St, F, B, S: Iterator, I: Iterator> SourceIter for Scan<I, St, F>
+unsafe impl<St, F, I> SourceIter for Scan<I, St, F>
where
- I: SourceIter<Source = S>,
- F: FnMut(&mut St, I::Item) -> Option<B>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
impl<I> FusedIterator for Skip<I> where I: FusedIterator {}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, I: Iterator> SourceIter for Skip<I>
+unsafe impl<I> SourceIter for Skip<I>
where
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, P, I: Iterator> SourceIter for SkipWhile<I, P>
+unsafe impl<P, I> SourceIter for SkipWhile<I, P>
where
- P: FnMut(&I::Item) -> bool,
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, I: Iterator> SourceIter for Take<I>
+unsafe impl<I> SourceIter for Take<I>
where
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
}
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S: Iterator, P, I: Iterator> SourceIter for TakeWhile<I, P>
+unsafe impl<P, I> SourceIter for TakeWhile<I, P>
where
- P: FnMut(&I::Item) -> bool,
- I: SourceIter<Source = S>,
+ I: SourceIter,
{
- type Source = S;
+ type Source = I::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut I::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.iter) }
}
// Arbitrarily selects the left side of the zip iteration as extractable "source"
// it would require negative trait bounds to be able to try both
#[unstable(issue = "none", feature = "inplace_iteration")]
-unsafe impl<S, A, B> SourceIter for Zip<A, B>
+unsafe impl<A, B> SourceIter for Zip<A, B>
where
- A: SourceIter<Source = S>,
- B: Iterator,
- S: Iterator,
+ A: SourceIter,
{
- type Source = S;
+ type Source = A::Source;
#[inline]
- unsafe fn as_inner(&mut self) -> &mut S {
+ unsafe fn as_inner(&mut self) -> &mut A::Source {
// SAFETY: unsafe function forwarding to unsafe function with the same requirements
unsafe { SourceIter::as_inner(&mut self.a) }
}