//! 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)*`.
/// Create a parallel iterator which simply wraps an inner type and delegates
/// all methods inward. The item type is parsed from the inner type.
///
/// The implementation of `IntoParallelIterator` should be added separately.
///
/// # Example
///
/// ```
/// delegate_iterator!{
/// #[doc = "Move items from `MyCollection` in parallel"]
/// MyIntoIter<T, U> => vec::IntoIter<(T, U)>,
/// impl<T: Ord + Send, U: Send>
/// }
/// ```
macro_rules! delegate_iterator {
($( #[ $attr:meta ] )+
$iter:ident < $( $i:tt ),* > => $( $inner:ident )::+ < $item:ty > ,
impl $( $args:tt )*
) => {
delegate_iterator_item!{
$( #[ $attr ] )+
$iter < $( $i ),* > => $( $inner )::+ < $item > : $item ,
impl $( $args )*
}
}
}
/// Create an indexed parallel iterator which simply wraps an inner type and
/// delegates all methods inward. The item type is parsed from the inner type.
macro_rules! delegate_indexed_iterator {
($( #[ $attr:meta ] )+
$iter:ident < $( $i:tt ),* > => $( $inner:ident )::+ < $item:ty > ,
impl $( $args:tt )*
) => {
delegate_indexed_iterator_item!{
$( #[ $attr ] )+
$iter < $( $i ),* > => $( $inner )::+ < $item > : $item ,
impl $( $args )*
}
}
}
/// Create a parallel iterator which simply wraps an inner type and delegates
/// all methods inward. The item type is explicitly specified.
///
/// The implementation of `IntoParallelIterator` should be added separately.
///
/// # Example
///
/// ```
/// delegate_iterator_item!{
/// #[doc = "Iterate items from `MyCollection` in parallel"]
/// MyIter<'a, T, U> => slice::Iter<'a, (T, U)>: &'a (T, U),
/// impl<'a, T: Ord + Sync, U: Sync>
/// }
/// ```
macro_rules! delegate_iterator_item {
($( #[ $attr:meta ] )+
$iter:ident < $( $i:tt ),* > => $inner:ty : $item:ty,
impl $( $args:tt )*
) => {
$( #[ $attr ] )+
pub struct $iter $( $args )* {
inner: $inner,
}
impl $( $args )* ParallelIterator for $iter < $( $i ),* > {
type Item = $item;
fn drive_unindexed<C>(self, consumer: C) -> C::Result
where C: UnindexedConsumer<Self::Item>
{
self.inner.drive_unindexed(consumer)
}
fn opt_len(&mut self) -> Option<usize> {
self.inner.opt_len()
}
}
}
}
/// Create an indexed parallel iterator which simply wraps an inner type and
/// delegates all methods inward. The item type is explicitly specified.
macro_rules! delegate_indexed_iterator_item {
($( #[ $attr:meta ] )+
$iter:ident < $( $i:tt ),* > => $inner:ty : $item:ty,
impl $( $args:tt )*
) => {
delegate_iterator_item!{
$( #[ $attr ] )+
$iter < $( $i ),* > => $inner : $item ,
impl $( $args )*
}
impl $( $args )* BoundedParallelIterator for $iter < $( $i ),* > {
fn upper_bound(&mut self) -> usize {
self.inner.upper_bound()
}
fn drive<C>(self, consumer: C) -> C::Result
where C: Consumer<Self::Item>
{
self.inner.drive(consumer)
}
}
impl $( $args )* ExactParallelIterator for $iter < $( $i ),* > {
fn len(&mut self) -> usize {
self.inner.len()
}
}
impl $( $args )* IndexedParallelIterator for $iter < $( $i ),* > {
fn with_producer<CB>(self, callback: CB) -> CB::Output
where CB: ProducerCallback<Self::Item>
{
self.inner.with_producer(callback)
}
}
}
}