diff options
Diffstat (limited to 'vendor/rayon/src/delegate.rs')
-rw-r--r-- | vendor/rayon/src/delegate.rs | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/vendor/rayon/src/delegate.rs b/vendor/rayon/src/delegate.rs new file mode 100644 index 0000000..2a6e331 --- /dev/null +++ b/vendor/rayon/src/delegate.rs @@ -0,0 +1,109 @@ +//! Macros for delegating newtype iterators to inner types. + +// Note: these place `impl` bounds at the end, as token gobbling is the only way +// I know how to consume an arbitrary list of constraints, with `$($args:tt)*`. + +/// Creates a parallel iterator implementation which simply wraps an inner type +/// and delegates all methods inward. The actual struct must already be +/// declared with an `inner` field. +/// +/// The implementation of `IntoParallelIterator` should be added separately. +macro_rules! delegate_iterator { + ($iter:ty => $item:ty , + impl $( $args:tt )* + ) => { + impl $( $args )* ParallelIterator for $iter { + type Item = $item; + + fn drive_unindexed<C>(self, consumer: C) -> C::Result + where C: UnindexedConsumer<Self::Item> + { + self.inner.drive_unindexed(consumer) + } + + fn opt_len(&self) -> Option<usize> { + self.inner.opt_len() + } + } + } +} + +/// Creates an indexed parallel iterator implementation which simply wraps an +/// inner type and delegates all methods inward. The actual struct must already +/// be declared with an `inner` field. +macro_rules! delegate_indexed_iterator { + ($iter:ty => $item:ty , + impl $( $args:tt )* + ) => { + delegate_iterator!{ + $iter => $item , + impl $( $args )* + } + + impl $( $args )* IndexedParallelIterator for $iter { + fn drive<C>(self, consumer: C) -> C::Result + where C: Consumer<Self::Item> + { + self.inner.drive(consumer) + } + + fn len(&self) -> usize { + self.inner.len() + } + + fn with_producer<CB>(self, callback: CB) -> CB::Output + where CB: ProducerCallback<Self::Item> + { + self.inner.with_producer(callback) + } + } + } +} + +#[test] +fn unindexed_example() { + use crate::collections::btree_map::IntoIter; + use crate::iter::plumbing::*; + use crate::prelude::*; + + use std::collections::BTreeMap; + + struct MyIntoIter<T: Ord + Send, U: Send> { + inner: IntoIter<T, U>, + } + + delegate_iterator! { + MyIntoIter<T, U> => (T, U), + impl<T: Ord + Send, U: Send> + } + + let map = BTreeMap::from([(1, 'a'), (2, 'b'), (3, 'c')]); + let iter = MyIntoIter { + inner: map.into_par_iter(), + }; + let vec: Vec<_> = iter.map(|(k, _)| k).collect(); + assert_eq!(vec, &[1, 2, 3]); +} + +#[test] +fn indexed_example() { + use crate::iter::plumbing::*; + use crate::prelude::*; + use crate::vec::IntoIter; + + struct MyIntoIter<T: Send> { + inner: IntoIter<T>, + } + + delegate_indexed_iterator! { + MyIntoIter<T> => T, + impl<T: Send> + } + + let iter = MyIntoIter { + inner: vec![1, 2, 3].into_par_iter(), + }; + let mut vec = vec![]; + iter.collect_into_vec(&mut vec); + assert_eq!(vec, &[1, 2, 3]); +} |