1use super::plumbing::*;
2use super::*;
3
4use std::iter;
5
6/// `Copied` is an iterator that copies the elements of an underlying iterator.
7///
8/// This struct is created by the [`copied()`] method on [`ParallelIterator`]
9///
10/// [`copied()`]: trait.ParallelIterator.html#method.copied
11/// [`ParallelIterator`]: trait.ParallelIterator.html
12#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
13#[derive(Debug, Clone)]
14pub struct Copied<I: ParallelIterator> {
15 base: I,
16}
17
18impl<I> Copied<I>
19where
20 I: ParallelIterator,
21{
22 /// Creates a new `Copied` iterator.
23 pub(super) fn new(base: I) -> Self {
24 Copied { base }
25 }
26}
27
28impl<'a, T, I> ParallelIterator for Copied<I>
29where
30 I: ParallelIterator<Item = &'a T>,
31 T: 'a + Copy + Send + Sync,
32{
33 type Item = T;
34
35 fn drive_unindexed<C>(self, consumer: C) -> C::Result
36 where
37 C: UnindexedConsumer<Self::Item>,
38 {
39 let consumer1 = CopiedConsumer::new(consumer);
40 self.base.drive_unindexed(consumer1)
41 }
42
43 fn opt_len(&self) -> Option<usize> {
44 self.base.opt_len()
45 }
46}
47
48impl<'a, T, I> IndexedParallelIterator for Copied<I>
49where
50 I: IndexedParallelIterator<Item = &'a T>,
51 T: 'a + Copy + Send + Sync,
52{
53 fn drive<C>(self, consumer: C) -> C::Result
54 where
55 C: Consumer<Self::Item>,
56 {
57 let consumer1 = CopiedConsumer::new(consumer);
58 self.base.drive(consumer1)
59 }
60
61 fn len(&self) -> usize {
62 self.base.len()
63 }
64
65 fn with_producer<CB>(self, callback: CB) -> CB::Output
66 where
67 CB: ProducerCallback<Self::Item>,
68 {
69 return self.base.with_producer(Callback { callback });
70
71 struct Callback<CB> {
72 callback: CB,
73 }
74
75 impl<'a, T, CB> ProducerCallback<&'a T> for Callback<CB>
76 where
77 CB: ProducerCallback<T>,
78 T: 'a + Copy + Send,
79 {
80 type Output = CB::Output;
81
82 fn callback<P>(self, base: P) -> CB::Output
83 where
84 P: Producer<Item = &'a T>,
85 {
86 let producer = CopiedProducer { base };
87 self.callback.callback(producer)
88 }
89 }
90 }
91}
92
93/// ////////////////////////////////////////////////////////////////////////
94
95struct CopiedProducer<P> {
96 base: P,
97}
98
99impl<'a, T, P> Producer for CopiedProducer<P>
100where
101 P: Producer<Item = &'a T>,
102 T: 'a + Copy,
103{
104 type Item = T;
105 type IntoIter = iter::Copied<P::IntoIter>;
106
107 fn into_iter(self) -> Self::IntoIter {
108 self.base.into_iter().copied()
109 }
110
111 fn min_len(&self) -> usize {
112 self.base.min_len()
113 }
114
115 fn max_len(&self) -> usize {
116 self.base.max_len()
117 }
118
119 fn split_at(self, index: usize) -> (Self, Self) {
120 let (left, right) = self.base.split_at(index);
121 (
122 CopiedProducer { base: left },
123 CopiedProducer { base: right },
124 )
125 }
126
127 fn fold_with<F>(self, folder: F) -> F
128 where
129 F: Folder<Self::Item>,
130 {
131 self.base.fold_with(CopiedFolder { base: folder }).base
132 }
133}
134
135/// ////////////////////////////////////////////////////////////////////////
136/// Consumer implementation
137
138struct CopiedConsumer<C> {
139 base: C,
140}
141
142impl<C> CopiedConsumer<C> {
143 fn new(base: C) -> Self {
144 CopiedConsumer { base }
145 }
146}
147
148impl<'a, T, C> Consumer<&'a T> for CopiedConsumer<C>
149where
150 C: Consumer<T>,
151 T: 'a + Copy,
152{
153 type Folder = CopiedFolder<C::Folder>;
154 type Reducer = C::Reducer;
155 type Result = C::Result;
156
157 fn split_at(self, index: usize) -> (Self, Self, Self::Reducer) {
158 let (left, right, reducer) = self.base.split_at(index);
159 (
160 CopiedConsumer::new(left),
161 CopiedConsumer::new(right),
162 reducer,
163 )
164 }
165
166 fn into_folder(self) -> Self::Folder {
167 CopiedFolder {
168 base: self.base.into_folder(),
169 }
170 }
171
172 fn full(&self) -> bool {
173 self.base.full()
174 }
175}
176
177impl<'a, T, C> UnindexedConsumer<&'a T> for CopiedConsumer<C>
178where
179 C: UnindexedConsumer<T>,
180 T: 'a + Copy,
181{
182 fn split_off_left(&self) -> Self {
183 CopiedConsumer::new(self.base.split_off_left())
184 }
185
186 fn to_reducer(&self) -> Self::Reducer {
187 self.base.to_reducer()
188 }
189}
190
191struct CopiedFolder<F> {
192 base: F,
193}
194
195impl<'a, T, F> Folder<&'a T> for CopiedFolder<F>
196where
197 F: Folder<T>,
198 T: 'a + Copy,
199{
200 type Result = F::Result;
201
202 fn consume(self, &item: &'a T) -> Self {
203 CopiedFolder {
204 base: self.base.consume(item),
205 }
206 }
207
208 fn consume_iter<I>(mut self, iter: I) -> Self
209 where
210 I: IntoIterator<Item = &'a T>,
211 {
212 self.base = self.base.consume_iter(iter.into_iter().copied());
213 self
214 }
215
216 fn complete(self) -> F::Result {
217 self.base.complete()
218 }
219
220 fn full(&self) -> bool {
221 self.base.full()
222 }
223}
224