Trait std::iter::TrustedLen
pub unsafe trait TrustedLen: Iterator { }
An iterator that reports an accurate length using size_hint.
The iterator reports a size hint where it is either exact (lower bound is equal to upper bound), or the upper bound is None
. The upper bound must only be None
if the actual iterator length is larger than usize::MAX
. In that case, the lower bound must be usize::MAX
, resulting in an Iterator::size_hint()
of (usize::MAX, None)
.
The iterator must produce exactly the number of elements it reported or diverge before reaching the end.
Safety
This trait must only be implemented when the contract is upheld. Consumers of this trait must inspect Iterator::size_hint()
’s upper bound.
Implementors
impl<'_> TrustedLen for Bytes<'_>
impl<'_, A> TrustedLen for std::option::Iter<'_, A>
impl<'_, A> TrustedLen for std::option::IterMut<'_, A>
impl<'_, A> TrustedLen for std::result::Iter<'_, A>
impl<'_, A> TrustedLen for std::result::IterMut<'_, A>
impl<'_, I> TrustedLen for &'_ mut I where
I: TrustedLen + ?Sized,
impl<'_, T> TrustedLen for std::collections::vec_deque::Iter<'_, T>
impl<'_, T> TrustedLen for std::collections::vec_deque::IterMut<'_, T>
impl<'_, T> TrustedLen for Chunks<'_, T>
impl<'_, T> TrustedLen for ChunksExact<'_, T>
impl<'_, T> TrustedLen for ChunksExactMut<'_, T>
impl<'_, T> TrustedLen for ChunksMut<'_, T>
impl<'_, T> TrustedLen for std::slice::Iter<'_, T>
impl<'_, T> TrustedLen for std::slice::IterMut<'_, T>
impl<'_, T> TrustedLen for RChunks<'_, T>
impl<'_, T> TrustedLen for RChunksExact<'_, T>
impl<'_, T> TrustedLen for RChunksExactMut<'_, T>
impl<'_, T> TrustedLen for RChunksMut<'_, T>
impl<'_, T> TrustedLen for Windows<'_, T>
impl<'_, T, const N: usize> TrustedLen for ArrayChunks<'_, T, N>
impl<'_, T, const N: usize> TrustedLen for ArrayChunksMut<'_, T, N>
impl<'a, I, T> TrustedLen for Cloned<I> where
T: 'a + Clone,
I: TrustedLen<Item = &'a T>,
impl<'a, I, T> TrustedLen for Copied<I> where
T: 'a + Copy,
I: TrustedLen<Item = &'a T>,
impl<'a, T, I, F, const N: usize> TrustedLen for FlatMap<I, &'a [T; N], F> where
F: FnMut(<I as Iterator>::Item) -> &'a [T; N],
I: TrustedLen,
impl<'a, T, I, F, const N: usize> TrustedLen for FlatMap<I, &'a mut [T; N], F> where
F: FnMut(<I as Iterator>::Item) -> &'a mut [T; N],
I: TrustedLen,
impl<A> TrustedLen for Range<A> where
A: TrustedStep,
impl<A> TrustedLen for RangeFrom<A> where
A: TrustedStep,
impl<A> TrustedLen for RangeInclusive<A> where
A: TrustedStep,
impl<A> TrustedLen for std::option::IntoIter<A>
impl<A> TrustedLen for std::result::IntoIter<A>
impl<A, B> TrustedLen for Chain<A, B> where
B: TrustedLen<Item = <A as Iterator>::Item>,
A: TrustedLen,
impl<A, B> TrustedLen for Zip<A, B> where
B: TrustedLen,
A: TrustedLen,
impl<B, I, F> TrustedLen for Map<I, F> where
F: FnMut(<I as Iterator>::Item) -> B,
I: TrustedLen,
impl<I> TrustedLen for Enumerate<I> where
I: TrustedLen,
impl<I> TrustedLen for Flatten<I> where
I: TrustedLen,
<I as Iterator>::Item: TrustedConstSize,
impl<I> TrustedLen for Fuse<I> where
I: TrustedLen,
impl<I> TrustedLen for Peekable<I> where
I: TrustedLen,
impl<I> TrustedLen for Rev<I> where
I: TrustedLen + DoubleEndedIterator,
impl<I> TrustedLen for Take<I> where
I: TrustedLen,
impl<T> TrustedLen for Empty<T>
impl<T> TrustedLen for Once<T>
impl<T, I, F, const N: usize> TrustedLen for FlatMap<I, [T; N], F> where
F: FnMut(<I as Iterator>::Item) -> [T; N],
I: TrustedLen,
impl<T, const N: usize> TrustedLen for std::array::IntoIter<T, N>
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/iter/trait.TrustedLen.html