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use crate::iter::adapters::{
zip::try_get_unchecked, TrustedRandomAccess, TrustedRandomAccessNoCoerce,
};
use crate::iter::{FusedIterator, TrustedLen};
use crate::ops::Try;
#[stable(feature = "iter_cloned", since = "1.1.0")]
#[must_use = "iterators are lazy and do nothing unless consumed"]
#[derive(Clone, Debug)]
pub struct Cloned<I> {
it: I,
}
impl<I> Cloned<I> {
pub(in crate::iter) fn new(it: I) -> Cloned<I> {
Cloned { it }
}
}
fn clone_try_fold<T: Clone, Acc, R>(mut f: impl FnMut(Acc, T) -> R) -> impl FnMut(Acc, &T) -> R {
move |acc, elt| f(acc, elt.clone())
}
#[stable(feature = "iter_cloned", since = "1.1.0")]
impl<'a, I, T: 'a> Iterator for Cloned<I>
where
I: Iterator<Item = &'a T>,
T: Clone,
{
type Item = T;
fn next(&mut self) -> Option<T> {
self.it.next().cloned()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.it.size_hint()
}
fn try_fold<B, F, R>(&mut self, init: B, f: F) -> R
where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Output = B>,
{
self.it.try_fold(init, clone_try_fold(f))
}
fn fold<Acc, F>(self, init: Acc, f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
self.it.map(T::clone).fold(init, f)
}
unsafe fn __iterator_get_unchecked(&mut self, idx: usize) -> T
where
Self: TrustedRandomAccessNoCoerce,
{
unsafe { try_get_unchecked(&mut self.it, idx).clone() }
}
}
#[stable(feature = "iter_cloned", since = "1.1.0")]
impl<'a, I, T: 'a> DoubleEndedIterator for Cloned<I>
where
I: DoubleEndedIterator<Item = &'a T>,
T: Clone,
{
fn next_back(&mut self) -> Option<T> {
self.it.next_back().cloned()
}
fn try_rfold<B, F, R>(&mut self, init: B, f: F) -> R
where
Self: Sized,
F: FnMut(B, Self::Item) -> R,
R: Try<Output = B>,
{
self.it.try_rfold(init, clone_try_fold(f))
}
fn rfold<Acc, F>(self, init: Acc, f: F) -> Acc
where
F: FnMut(Acc, Self::Item) -> Acc,
{
self.it.map(T::clone).rfold(init, f)
}
}
#[stable(feature = "iter_cloned", since = "1.1.0")]
impl<'a, I, T: 'a> ExactSizeIterator for Cloned<I>
where
I: ExactSizeIterator<Item = &'a T>,
T: Clone,
{
fn len(&self) -> usize {
self.it.len()
}
fn is_empty(&self) -> bool {
self.it.is_empty()
}
}
#[stable(feature = "fused", since = "1.26.0")]
impl<'a, I, T: 'a> FusedIterator for Cloned<I>
where
I: FusedIterator<Item = &'a T>,
T: Clone,
{
}
#[doc(hidden)]
#[unstable(feature = "trusted_random_access", issue = "none")]
unsafe impl<I> TrustedRandomAccess for Cloned<I> where I: TrustedRandomAccess {}
#[doc(hidden)]
#[unstable(feature = "trusted_random_access", issue = "none")]
unsafe impl<I> TrustedRandomAccessNoCoerce for Cloned<I>
where
I: TrustedRandomAccessNoCoerce,
{
const MAY_HAVE_SIDE_EFFECT: bool = true;
}
#[unstable(feature = "trusted_len", issue = "37572")]
unsafe impl<'a, I, T: 'a> TrustedLen for Cloned<I>
where
I: TrustedLen<Item = &'a T>,
T: Clone,
{
}
