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use crate::iter::plumbing::*;
use crate::iter::*;
use std::ops::RangeInclusive;
#[derive(Debug, Clone)]
pub struct Iter<T> {
range: RangeInclusive<T>,
}
impl<T> Iter<T>
where
RangeInclusive<T>: Clone + Iterator<Item = T> + DoubleEndedIterator,
{
fn bounds(&self) -> Option<(T, T)> {
Some((self.range.clone().next()?, self.range.clone().next_back()?))
}
}
impl<T> IntoParallelIterator for RangeInclusive<T>
where
Iter<T>: ParallelIterator,
{
type Item = <Iter<T> as ParallelIterator>::Item;
type Iter = Iter<T>;
fn into_par_iter(self) -> Self::Iter {
Iter { range: self }
}
}
macro_rules! convert {
( $self:ident . $method:ident ( $( $arg:expr ),* ) ) => {
if let Some((start, end)) = $self.bounds() {
if let Some(end) = end.checked_add(1) {
(start..end).into_par_iter().$method($( $arg ),*)
} else {
(start..end).into_par_iter().chain(once(end)).$method($( $arg ),*)
}
} else {
empty::<Self::Item>().$method($( $arg ),*)
}
};
}
macro_rules! parallel_range_impl {
( $t:ty ) => {
impl ParallelIterator for Iter<$t> {
type Item = $t;
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where
C: UnindexedConsumer<Self::Item>,
{
convert!(self.drive_unindexed(consumer))
}
fn opt_len(&self) -> Option<usize> {
convert!(self.opt_len())
}
}
};
}
macro_rules! indexed_range_impl {
( $t:ty ) => {
parallel_range_impl! { $t }
impl IndexedParallelIterator for Iter<$t> {
fn drive<C>(self, consumer: C) -> C::Result
where
C: Consumer<Self::Item>,
{
convert!(self.drive(consumer))
}
fn len(&self) -> usize {
self.range.len()
}
fn with_producer<CB>(self, callback: CB) -> CB::Output
where
CB: ProducerCallback<Self::Item>,
{
convert!(self.with_producer(callback))
}
}
};
}
indexed_range_impl! {u8}
indexed_range_impl! {u16}
indexed_range_impl! {i8}
indexed_range_impl! {i16}
parallel_range_impl! {usize}
parallel_range_impl! {isize}
parallel_range_impl! {u32}
parallel_range_impl! {i32}
parallel_range_impl! {u64}
parallel_range_impl! {i64}
parallel_range_impl! {u128}
parallel_range_impl! {i128}
#[test]
#[cfg(target_pointer_width = "64")]
fn test_u32_opt_len() {
use std::u32;
assert_eq!(Some(101), (0..=100u32).into_par_iter().opt_len());
assert_eq!(
Some(u32::MAX as usize),
(0..=u32::MAX - 1).into_par_iter().opt_len()
);
assert_eq!(
Some(u32::MAX as usize + 1),
(0..=u32::MAX).into_par_iter().opt_len()
);
}
#[test]
fn test_u64_opt_len() {
use std::{u64, usize};
assert_eq!(Some(101), (0..=100u64).into_par_iter().opt_len());
assert_eq!(
Some(usize::MAX),
(0..=usize::MAX as u64 - 1).into_par_iter().opt_len()
);
assert_eq!(None, (0..=usize::MAX as u64).into_par_iter().opt_len());
assert_eq!(None, (0..=u64::MAX).into_par_iter().opt_len());
}
#[test]
fn test_u128_opt_len() {
use std::{u128, usize};
assert_eq!(Some(101), (0..=100u128).into_par_iter().opt_len());
assert_eq!(
Some(usize::MAX),
(0..=usize::MAX as u128 - 1).into_par_iter().opt_len()
);
assert_eq!(None, (0..=usize::MAX as u128).into_par_iter().opt_len());
assert_eq!(None, (0..=u128::MAX).into_par_iter().opt_len());
}
#[test]
#[cfg(target_pointer_width = "64")]
fn test_usize_i64_overflow() {
use crate::ThreadPoolBuilder;
use std::i64;
let iter = (-2..=i64::MAX).into_par_iter();
assert_eq!(iter.opt_len(), Some(i64::MAX as usize + 3));
let pool = ThreadPoolBuilder::new().num_threads(8).build().unwrap();
pool.install(|| assert_eq!(iter.find_last(|_| true), Some(i64::MAX)));
}