use super::plumbing::*;
use super::*;
use std::iter;
/// `Copied` is an iterator that copies the elements of an underlying iterator.
///
/// This struct is created by the [`copied()`] method on [`ParallelIterator`]
///
/// [`copied()`]: trait.ParallelIterator.html#method.copied
/// [`ParallelIterator`]: trait.ParallelIterator.html
#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
#[derive(Debug, Clone)]
pub struct Copied<I: ParallelIterator> {
base: I,
}
impl<I> Copied<I>
where
I: ParallelIterator,
{
/// Creates a new `Copied` iterator.
pub(super) fn new(base: I) -> Self {
Copied { base }
}
}
impl<'a, T, I> ParallelIterator for Copied<I>
where
I: ParallelIterator<Item = &'a T>,
T: 'a + Copy + Send + Sync,
{
type Item = T;
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
let consumer1 = CopiedConsumer::new(consumer);
self.base.drive_unindexed(consumer1)
}
fn opt_len(&self) -> Option<usize> {
self.base.opt_len()
}
}
impl<'a, T, I> IndexedParallelIterator for Copied<I>
where
I: IndexedParallelIterator<Item = &'a T>,
T: 'a + Copy + Send + Sync,
{
fn drive<C>(self, consumer: C) -> C::Result
where
C: Consumer<Self::Item>,
{
let consumer1 = CopiedConsumer::new(consumer);
self.base.drive(consumer1)
}
fn len(&self) -> usize {
self.base.len()
}
fn with_producer<CB>(self, callback: CB) -> CB::Output
where
CB: ProducerCallback<Self::Item>,
{
return self.base.with_producer(Callback { callback });
struct Callback<CB> {
callback: CB,
}
impl<'a, T, CB> ProducerCallback<&'a T> for Callback<CB>
where
CB: ProducerCallback<T>,
T: 'a + Copy + Send,
{
type Output = CB::Output;
fn callback<P>(self, base: P) -> CB::Output
where
P: Producer<Item = &'a T>,
{
let producer = CopiedProducer { base };
self.callback.callback(producer)
}
}
}
}
/// ////////////////////////////////////////////////////////////////////////
struct CopiedProducer<P> {
base: P,
}
impl<'a, T, P> Producer for CopiedProducer<P>
where
P: Producer<Item = &'a T>,
T: 'a + Copy,
{
type Item = T;
type IntoIter = iter::Copied<P::IntoIter>;
fn into_iter(self) -> Self::IntoIter {
self.base.into_iter().copied()
}
fn min_len(&self) -> usize {
self.base.min_len()
}
fn max_len(&self) -> usize {
self.base.max_len()
}
fn split_at(self, index: usize) -> (Self, Self) {
let (left, right) = self.base.split_at(index);
(
CopiedProducer { base: left },
CopiedProducer { base: right },
)
}
fn fold_with<F>(self, folder: F) -> F
where
F: Folder<Self::Item>,
{
self.base.fold_with(CopiedFolder { base: folder }).base
}
}
/// ////////////////////////////////////////////////////////////////////////
/// Consumer implementation
struct CopiedConsumer<C> {
base: C,
}
impl<C> CopiedConsumer<C> {
fn new(base: C) -> Self {
CopiedConsumer { base }
}
}
impl<'a, T, C> Consumer<&'a T> for CopiedConsumer<C>
where
C: Consumer<T>,
T: 'a + Copy,
{
type Folder = CopiedFolder<C::Folder>;
type Reducer = C::Reducer;
type Result = C::Result;
fn split_at(self, index: usize) -> (Self, Self, Self::Reducer) {
let (left, right, reducer) = self.base.split_at(index);
(
CopiedConsumer::new(left),
CopiedConsumer::new(right),
reducer,
)
}
fn into_folder(self) -> Self::Folder {
CopiedFolder {
base: self.base.into_folder(),
}
}
fn full(&self) -> bool {
self.base.full()
}
}
impl<'a, T, C> UnindexedConsumer<&'a T> for CopiedConsumer<C>
where
C: UnindexedConsumer<T>,
T: 'a + Copy,
{
fn split_off_left(&self) -> Self {
CopiedConsumer::new(self.base.split_off_left())
}
fn to_reducer(&self) -> Self::Reducer {
self.base.to_reducer()
}
}
struct CopiedFolder<F> {
base: F,
}
impl<'a, T, F> Folder<&'a T> for CopiedFolder<F>
where
F: Folder<T>,
T: 'a + Copy,
{
type Result = F::Result;
fn consume(self, &item: &'a T) -> Self {
CopiedFolder {
base: self.base.consume(item),
}
}
fn consume_iter<I>(mut self, iter: I) -> Self
where
I: IntoIterator<Item = &'a T>,
{
self.base = self.base.consume_iter(iter.into_iter().copied());
self
}
fn complete(self) -> F::Result {
self.base.complete()
}
fn full(&self) -> bool {
self.base.full()
}
}
