Trait std::iter::TrustedLen [−][src]
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 a .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 .size_hint
’s upper bound.
Implementors
impl TrustedLen for Range<i16>
impl TrustedLen for RangeInclusive<u32>
impl<'a, A> TrustedLen for std::option::Iter<'a, A>
impl<B, I, F> TrustedLen for Map<I, F> where
F: FnMut(<I as Iterator>::Item) -> B,
I: TrustedLen,impl<'a, T> TrustedLen for ExactChunks<'a, T>
impl TrustedLen for RangeInclusive<i32>
impl TrustedLen for RangeInclusive<i64>
impl TrustedLen for RangeInclusive<u16>
impl<'a, I, T> TrustedLen for Cloned<I> where
I: TrustedLen<Item = &'a T>,
T: 'a + Clone,impl<A> TrustedLen for RangeFrom<A> where
A: Step,impl<T> TrustedLen for Empty<T>
impl<'a, T> TrustedLen for Windows<'a, T>
impl<T> TrustedLen for Once<T>
impl<A, B> TrustedLen for Zip<A, B> where
A: TrustedLen,
B: TrustedLen,impl TrustedLen for Range<u8>
impl<'a, I> TrustedLen for &'a mut I where
I: TrustedLen + ?Sized,impl TrustedLen for Range<i8>
impl<A, B> TrustedLen for Chain<A, B> where
A: TrustedLen,
B: TrustedLen<Item = <A as Iterator>::Item>,impl TrustedLen for RangeInclusive<i8>
impl<'a, A> TrustedLen for std::result::Iter<'a, A>
impl<A> TrustedLen for std::result::IntoIter<A>
impl TrustedLen for RangeInclusive<u8>
impl<'a, T> TrustedLen for ExactChunksMut<'a, T>
impl TrustedLen for Range<usize>
impl TrustedLen for Range<u16>
impl<A> TrustedLen for Repeat<A> where
A: Clone,impl<A> TrustedLen for std::option::IntoIter<A>
impl<'a, T> TrustedLen for std::slice::Iter<'a, T>
impl TrustedLen for RangeInclusive<u64>
impl TrustedLen for Range<u32>
impl TrustedLen for Range<i64>
impl TrustedLen for Range<isize>
impl TrustedLen for Range<u64>
impl<'a, T> TrustedLen for Chunks<'a, T>
impl<'a, T> TrustedLen for ChunksMut<'a, T>
impl<I> TrustedLen for Rev<I> where
I: TrustedLen + DoubleEndedIterator,impl TrustedLen for RangeInclusive<isize>
impl<'a> TrustedLen for Bytes<'a>
impl TrustedLen for Range<i32>
impl<'a, T> TrustedLen for std::slice::IterMut<'a, T>
impl<I> TrustedLen for Take<I> where
I: TrustedLen,impl TrustedLen for RangeInclusive<usize>
impl<'a, A> TrustedLen for std::result::IterMut<'a, A>
impl<I> TrustedLen for Enumerate<I> where
I: TrustedLen,impl TrustedLen for RangeInclusive<i16>
impl<'a, A> TrustedLen for std::option::IterMut<'a, A>
impl<A, F> TrustedLen for RepeatWith<F> where
F: FnMut() -> A,impl<T> TrustedLen for std::vec::IntoIter<T>