build: resolve warnings

Co-authored-by: warren2k <846021+warren2k@users.noreply.github.com>

benches/fold_specialization.rs

@@ -1,3 +1,5 @@
+#![allow(unstable_name_collisions)]
+
 use criterion::{criterion_group, criterion_main, Criterion};
 use itertools::Itertools;
 

benches/tree_fold1.rs

@@ -1,3 +1,5 @@
+#![allow(deprecated)]
+
 use criterion::{criterion_group, criterion_main, Criterion};
 use itertools::{cloned, Itertools};
 

src/size_hint.rs

@@ -29,6 +29,7 @@ pub fn add_scalar(sh: SizeHint, x: usize) -> SizeHint {
 }
 
 /// Subtract `x` correctly from a `SizeHint`.
+#[cfg(feature = "use_alloc")]
 #[inline]
 pub fn sub_scalar(sh: SizeHint, x: usize) -> SizeHint {
     let (mut low, mut hi) = sh;

tests/quick.rs

@@ -3,6 +3,8 @@
 //!
 //! In particular we test the tedious size_hint and exact size correctness.
 
+#![allow(deprecated, unstable_name_collisions)]
+
 use itertools::free::{
     cloned, enumerate, multipeek, peek_nth, put_back, put_back_n, rciter, zip, zip_eq,
 };

tests/specializations.rs

@@ -1,3 +1,5 @@
+#![allow(unstable_name_collisions)]
+
 use itertools::Itertools;
 use quickcheck::quickcheck;
 use std::fmt::Debug;

tests/test_core.rs

@@ -4,6 +4,7 @@
 //! option. This file may not be copied, modified, or distributed
 //! except according to those terms.
 #![no_std]
+#![allow(deprecated)]
 
 use crate::it::chain;
 use crate::it::free::put_back;

tests/test_std.rs

@@ -1,3 +1,5 @@
+#![allow(unstable_name_collisions)]
+
 use crate::it::cloned;
 use crate::it::free::put_back_n;
 use crate::it::free::rciter;