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