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