lender/adapters/
owned.rs

1use alloc::borrow::ToOwned;
2use core::iter::FusedIterator;
3
4use crate::{DoubleEndedLender, ExactSizeLender, FusedLender, Lend, Lender};
5
6/// An iterator that converts each lent reference into an owned value.
7///
8/// This `struct` is created by the [`owned()`](crate::Lender::owned) method
9/// on [`Lender`].
10#[derive(Clone, Debug)]
11#[must_use = "iterators are lazy and do nothing unless consumed"]
12pub struct Owned<L> {
13    pub(crate) lender: L,
14}
15
16impl<L> Owned<L> {
17    #[inline(always)]
18    pub(crate) fn new(lender: L) -> Self {
19        Self { lender }
20    }
21
22    /// Returns the inner lender.
23    #[inline(always)]
24    pub fn into_inner(self) -> L {
25        self.lender
26    }
27}
28
29impl<T, L> Iterator for Owned<L>
30where
31    L: Lender,
32    for<'all> Lend<'all, L>: ToOwned<Owned = T>,
33{
34    type Item = T;
35    #[inline]
36    fn next(&mut self) -> Option<Self::Item> {
37        self.lender.next().map(|ref x| x.to_owned())
38    }
39
40    #[inline(always)]
41    fn size_hint(&self) -> (usize, Option<usize>) {
42        self.lender.size_hint()
43    }
44
45    #[inline]
46    fn fold<B, F>(self, init: B, mut f: F) -> B
47    where
48        F: FnMut(B, Self::Item) -> B,
49    {
50        self.lender.fold(init, |acc, ref x| f(acc, x.to_owned()))
51    }
52
53    #[inline(always)]
54    fn count(self) -> usize {
55        self.lender.count()
56    }
57
58    #[inline]
59    fn nth(&mut self, n: usize) -> Option<Self::Item> {
60        self.lender.nth(n).map(|ref x| x.to_owned())
61    }
62}
63
64impl<T, L> DoubleEndedIterator for Owned<L>
65where
66    L: DoubleEndedLender,
67    for<'all> Lend<'all, L>: ToOwned<Owned = T>,
68{
69    #[inline]
70    fn next_back(&mut self) -> Option<Self::Item> {
71        self.lender.next_back().map(|ref x| x.to_owned())
72    }
73
74    #[inline]
75    fn rfold<B, F>(self, init: B, mut f: F) -> B
76    where
77        F: FnMut(B, Self::Item) -> B,
78    {
79        self.lender.rfold(init, |acc, ref x| f(acc, x.to_owned()))
80    }
81}
82
83impl<T, L> ExactSizeIterator for Owned<L>
84where
85    L: ExactSizeLender,
86    for<'all> Lend<'all, L>: ToOwned<Owned = T>,
87{
88    #[inline(always)]
89    fn len(&self) -> usize {
90        self.lender.len()
91    }
92}
93
94impl<T, L> FusedIterator for Owned<L>
95where
96    L: FusedLender,
97    for<'all> Lend<'all, L>: ToOwned<Owned = T>,
98{
99}
100
101impl<L> Default for Owned<L>
102where
103    L: Default,
104{
105    #[inline(always)]
106    fn default() -> Self {
107        Self::new(L::default())
108    }
109}
lender/adapters/owned.rs

lender/adapters/
owned.rs
