Add must_use attribute to iterator trait and impl

1 files changed, 2 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 3442f58..7022d37 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -42,6 +42,7 @@ use std::{collections::HashMap, num::NonZeroUsize};
 use crossbeam_channel::{Receiver, Select, Sender, TryRecvError};
 
 /// An extension trait adding parallel sequential mapping to the standard [`Iterator`] trait.
+#[must_use = "iterators are lazy and do nothing unless consumed"]
 pub trait ParallelIterator {
     /// Creates an iterator which applies a given closure to each element in parallel.
     ///
@@ -146,6 +147,7 @@ impl<I> ParallelIterator for I where I: Iterator {}
 ///
 /// This struct is created by the [`map_parallel`](ParallelIterator::map_parallel) method on the
 /// [`ParallelIterator`] trait.
+#[must_use = "iterators are lazy and do nothing unless consumed"]
 pub struct ParallelMap<I, B>
 where
     I: Iterator,