From a97d8a3dbdb90be442c307fb1e80319bdb293c3e Mon Sep 17 00:00:00 2001
From: Philippe-Cholet <phcholet@orange.fr>
Date: Fri, 3 Nov 2023 19:12:48 +0100
Subject: [PATCH] Add missing `must_use` attributes on adaptors

---
 src/adaptors/mod.rs                  | 1 +
 src/combinations_with_replacement.rs | 1 +
 src/multipeek_impl.rs                | 1 +
 src/peek_nth.rs                      | 1 +
 src/put_back_n_impl.rs               | 1 +
 src/rciter_impl.rs                   | 1 +
 6 files changed, 6 insertions(+)

diff --git a/src/adaptors/mod.rs b/src/adaptors/mod.rs
index a19cd0e04..7d05a70b3 100644
--- a/src/adaptors/mod.rs
+++ b/src/adaptors/mod.rs
@@ -185,6 +185,7 @@ where
 /// item to the front of the iterator.
 ///
 /// Iterator element type is `I::Item`.
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 pub struct PutBack<I>
 where
     I: Iterator,
diff --git a/src/combinations_with_replacement.rs b/src/combinations_with_replacement.rs
index f1a0bc07d..88d858b5f 100644
--- a/src/combinations_with_replacement.rs
+++ b/src/combinations_with_replacement.rs
@@ -10,6 +10,7 @@ use crate::adaptors::checked_binomial;
 /// See [`.combinations_with_replacement()`](crate::Itertools::combinations_with_replacement)
 /// for more information.
 #[derive(Clone)]
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 pub struct CombinationsWithReplacement<I>
 where
     I: Iterator,
diff --git a/src/multipeek_impl.rs b/src/multipeek_impl.rs
index 339cf9781..00c5d4ea7 100644
--- a/src/multipeek_impl.rs
+++ b/src/multipeek_impl.rs
@@ -7,6 +7,7 @@ use std::iter::Fuse;
 
 /// See [`multipeek()`] for more information.
 #[derive(Clone, Debug)]
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 pub struct MultiPeek<I>
 where
     I: Iterator,
diff --git a/src/peek_nth.rs b/src/peek_nth.rs
index 5f7fb9396..e8546030d 100644
--- a/src/peek_nth.rs
+++ b/src/peek_nth.rs
@@ -5,6 +5,7 @@ use std::iter::Fuse;
 
 /// See [`peek_nth()`] for more information.
 #[derive(Clone, Debug)]
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 pub struct PeekNth<I>
 where
     I: Iterator,
diff --git a/src/put_back_n_impl.rs b/src/put_back_n_impl.rs
index 5fdbd5a98..9b23fa7d5 100644
--- a/src/put_back_n_impl.rs
+++ b/src/put_back_n_impl.rs
@@ -7,6 +7,7 @@ use crate::size_hint;
 ///
 /// Iterator element type is `I::Item`.
 #[derive(Debug, Clone)]
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 pub struct PutBackN<I: Iterator> {
     top: Vec<I::Item>,
     iter: I,
diff --git a/src/rciter_impl.rs b/src/rciter_impl.rs
index 1282ae865..e3b753206 100644
--- a/src/rciter_impl.rs
+++ b/src/rciter_impl.rs
@@ -4,6 +4,7 @@ use std::iter::{FusedIterator, IntoIterator};
 
 /// A wrapper for `Rc<RefCell<I>>`, that implements the `Iterator` trait.
 #[derive(Debug)]
+#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
 pub struct RcIter<I> {
     /// The boxed iterator.
     pub rciter: Rc<RefCell<I>>,