diff --git a/src/adaptors/map.rs b/src/adaptors/map.rs
index ce7c762cb..ff377f700 100644
--- a/src/adaptors/map.rs
+++ b/src/adaptors/map.rs
@@ -68,7 +68,7 @@ where
 pub type MapOk<I, F> = MapSpecialCase<I, MapSpecialCaseFnOk<F>>;
 
 /// See [`MapOk`](struct.MapOk.html).
-#[deprecated(note = "Use MapOk instead", since = "0.10")]
+#[deprecated(note = "Use MapOk instead", since = "0.10.0")]
 pub type MapResults<I, F> = MapOk<I, F>;
 
 impl<F, T, U, E> MapSpecialCaseFn<Result<T, E>> for MapSpecialCaseFnOk<F>
diff --git a/src/adaptors/mod.rs b/src/adaptors/mod.rs
index d98f6fe7c..0b9d1185f 100644
--- a/src/adaptors/mod.rs
+++ b/src/adaptors/mod.rs
@@ -113,22 +113,11 @@ impl<I, J> Iterator for InterleaveShortest<I, J>
 
     #[inline]
     fn next(&mut self) -> Option<Self::Item> {
-        match self.phase {
-            false => match self.it0.next() {
-                None => None,
-                e => {
-                    self.phase = true;
-                    e
-                }
-            },
-            true => match self.it1.next() {
-                None => None,
-                e => {
-                    self.phase = false;
-                    e
-                }
-            },
+        let e = if self.phase { self.it1.next() } else { self.it0.next() };
+        if e.is_some() {
+            self.phase = !self.phase;
         }
+        e
     }
 
     #[inline]
@@ -412,7 +401,7 @@ impl<B, F, I> Iterator for Batching<I, F>
 /// then skipping forward *n-1* elements.
 ///
 /// See [`.step()`](../trait.Itertools.html#method.step) for more information.
-#[deprecated(note="Use std .step_by() instead", since="0.8")]
+#[deprecated(note="Use std .step_by() instead", since="0.8.0")]
 #[allow(deprecated)]
 #[derive(Clone, Debug)]
 #[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
diff --git a/src/adaptors/multi_product.rs b/src/adaptors/multi_product.rs
index 4a31713ab..532333a48 100644
--- a/src/adaptors/multi_product.rs
+++ b/src/adaptors/multi_product.rs
@@ -161,7 +161,7 @@ impl<I> Iterator for MultiProduct<I>
     }
 
     fn count(self) -> usize {
-        if self.0.len() == 0 {
+        if self.0.is_empty() {
             return 0;
         }
 
@@ -183,7 +183,7 @@ impl<I> Iterator for MultiProduct<I>
 
     fn size_hint(&self) -> (usize, Option<usize>) {
         // Not ExactSizeIterator because size may be larger than usize
-        if self.0.len() == 0 {
+        if self.0.is_empty() {
             return (0, Some(0));
         }
 
diff --git a/src/combinations.rs b/src/combinations.rs
index 875951808..a8b612f17 100644
--- a/src/combinations.rs
+++ b/src/combinations.rs
@@ -56,7 +56,7 @@ impl<I> Iterator for Combinations<I>
                 return None;
             }
             self.first = false;
-        } else if self.indices.len() == 0 {
+        } else if self.indices.is_empty() {
             return None;
         } else {
             // Scan from the end, looking for an index to increment
diff --git a/src/concat_impl.rs b/src/concat_impl.rs
index 6048d18f6..0233d01f6 100644
--- a/src/concat_impl.rs
+++ b/src/concat_impl.rs
@@ -18,5 +18,5 @@ pub fn concat<I>(iterable: I) -> I::Item
     where I: IntoIterator,
           I::Item: Extend<<<I as IntoIterator>::Item as IntoIterator>::Item> + IntoIterator + Default
 {
-    iterable.into_iter().fold1(|mut a, b| { a.extend(b); a }).unwrap_or_else(|| <_>::default())
+    iterable.into_iter().fold1(|mut a, b| { a.extend(b); a }).unwrap_or_else(<_>::default)
 }
diff --git a/src/cons_tuples_impl.rs b/src/cons_tuples_impl.rs
index 3cdfe0d18..f2736ad13 100644
--- a/src/cons_tuples_impl.rs
+++ b/src/cons_tuples_impl.rs
@@ -57,8 +57,8 @@ impl<I, J> Clone for ConsTuples<I, J>
 
 /// Create an iterator that maps for example iterators of
 /// `((A, B), C)` to `(A, B, C)`.
-pub fn cons_tuples<I, J>(iterable: I) -> ConsTuples<I, J>
-    where I: Iterator<Item=J>
+pub fn cons_tuples<I, J>(iterable: I) -> ConsTuples<I::IntoIter, J>
+    where I: IntoIterator<Item=J>
 {
     ConsTuples { iter: iterable.into_iter() }
 }
diff --git a/src/format.rs b/src/format.rs
index f72ed3917..3a8b2977e 100644
--- a/src/format.rs
+++ b/src/format.rs
@@ -28,7 +28,7 @@ pub struct Format<'a, I> {
     inner: RefCell<Option<I>>,
 }
 
-pub fn new_format<'a, I, F>(iter: I, separator: &'a str, f: F) -> FormatWith<'a, I, F>
+pub fn new_format<I, F>(iter: I, separator: &str, f: F) -> FormatWith<'_, I, F>
     where I: Iterator,
           F: FnMut(I::Item, &mut dyn FnMut(&dyn fmt::Display) -> fmt::Result) -> fmt::Result
 {
@@ -38,7 +38,7 @@ pub fn new_format<'a, I, F>(iter: I, separator: &'a str, f: F) -> FormatWith<'a,
     }
 }
 
-pub fn new_format_default<'a, I>(iter: I, separator: &'a str) -> Format<'a, I>
+pub fn new_format_default<I>(iter: I, separator: &str) -> Format<'_, I>
     where I: Iterator,
 {
     Format {
@@ -60,7 +60,7 @@ impl<'a, I, F> fmt::Display for FormatWith<'a, I, F>
         if let Some(fst) = iter.next() {
             format(fst, &mut |disp: &dyn fmt::Display| disp.fmt(f))?;
             for elt in iter {
-                if self.sep.len() > 0 {
+                if !self.sep.is_empty() {
 
                     f.write_str(self.sep)?;
                 }
@@ -85,7 +85,7 @@ impl<'a, I> Format<'a, I>
         if let Some(fst) = iter.next() {
             cb(&fst, f)?;
             for elt in iter {
-                if self.sep.len() > 0 {
+                if !self.sep.is_empty() {
                     f.write_str(self.sep)?;
                 }
                 cb(&elt, f)?;
diff --git a/src/group_map.rs b/src/group_map.rs
index 2d219e92a..9787adc7f 100644
--- a/src/group_map.rs
+++ b/src/group_map.rs
@@ -15,7 +15,7 @@ pub fn into_group_map<I, K, V>(iter: I) -> HashMap<K, Vec<V>>
     let mut lookup = HashMap::new();
 
     for (key, val) in iter {
-        lookup.entry(key).or_insert(Vec::new()).push(val);
+        lookup.entry(key).or_insert_with(Vec::new).push(val);
     }
 
     lookup
@@ -30,5 +30,3 @@ pub fn into_group_map_by<I, K, V>(iter: I, f: impl Fn(&V) -> K) -> HashMap<K, Ve
         iter.map(|v| (f(&v), v))
     )
 }
-
-
diff --git a/src/intersperse.rs b/src/intersperse.rs
index a17ba8328..a0d79b036 100644
--- a/src/intersperse.rs
+++ b/src/intersperse.rs
@@ -62,7 +62,7 @@ pub fn intersperse_with<I, ElemF>(iter: I, elt: ElemF) -> IntersperseWith<I, Ele
     let mut iter = iter.fuse();
     IntersperseWith {
         peek: iter.next(),
-        iter: iter,
+        iter,
         element: elt,
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 1412930b1..4c10178fd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -728,7 +728,7 @@ pub trait Itertools : Iterator {
     /// let it = (0..8).step(3);
     /// itertools::assert_equal(it, vec![0, 3, 6]);
     /// ```
-    #[deprecated(note="Use std .step_by() instead", since="0.8")]
+    #[deprecated(note="Use std .step_by() instead", since="0.8.0")]
     #[allow(deprecated)]
     fn step(self, n: usize) -> Step<Self>
         where Self: Sized
@@ -751,7 +751,7 @@ pub trait Itertools : Iterator {
     }
 
     /// See [`.map_ok()`](#method.map_ok).
-    #[deprecated(note="Use .map_ok() instead", since="0.10")]
+    #[deprecated(note="Use .map_ok() instead", since="0.10.0")]
     fn map_results<F, T, U, E>(self, f: F) -> MapOk<Self, F>
         where Self: Iterator<Item = Result<T, E>> + Sized,
               F: FnMut(T) -> U,
@@ -1651,7 +1651,7 @@ pub trait Itertools : Iterator {
     ///
     /// itertools::assert_equal(rx.iter(), vec![1, 3, 5, 7, 9]);
     /// ```
-    #[deprecated(note="Use .for_each() instead", since="0.8")]
+    #[deprecated(note="Use .for_each() instead", since="0.8.0")]
     fn foreach<F>(self, f: F)
         where F: FnMut(Self::Item),
               Self: Sized,
@@ -1839,7 +1839,7 @@ pub trait Itertools : Iterator {
     }
 
     /// See [`.fold_ok()`](#method.fold_ok).
-    #[deprecated(note="Use .fold_ok() instead", since="0.10")]
+    #[deprecated(note="Use .fold_ok() instead", since="0.10.0")]
     fn fold_results<A, E, B, F>(&mut self, start: B, f: F) -> Result<B, E>
         where Self: Iterator<Item = Result<A, E>>,
               F: FnMut(B, A) -> B
@@ -2099,13 +2099,13 @@ pub trait Itertools : Iterator {
     /// The big difference between the computations of `result2` and `result3` is that while
     /// `fold()` called the provided closure for every item of the callee iterator,
     /// `fold_while()` actually stopped iterating as soon as it encountered `Fold::Done(_)`.
-    #[deprecated(note="Use .try_fold() instead", since="0.8")]
+    #[deprecated(note="Use .try_fold() instead", since="0.8.0")]
     fn fold_while<B, F>(&mut self, init: B, mut f: F) -> FoldWhile<B>
         where Self: Sized,
               F: FnMut(B, Self::Item) -> FoldWhile<B>
     {
         let mut acc = init;
-        while let Some(item) = self.next() {
+        for item in self {
             match f(acc, item) {
                 FoldWhile::Continue(res) => acc = res,
                 res @ FoldWhile::Done(_) => return res,
diff --git a/src/size_hint.rs b/src/size_hint.rs
index be54443f2..9d9b8b8a1 100644
--- a/src/size_hint.rs
+++ b/src/size_hint.rs
@@ -10,7 +10,7 @@ pub type SizeHint = (usize, Option<usize>);
 /// Add **SizeHint** correctly.
 #[inline]
 pub fn add(a: SizeHint, b: SizeHint) -> SizeHint {
-    let min = a.0.checked_add(b.0).unwrap_or(usize::MAX);
+    let min = a.0.saturating_add(b.0);
     let max = match (a.1, b.1) {
         (Some(x), Some(y)) => x.checked_add(y),
         _ => None,
@@ -56,7 +56,7 @@ pub fn sub_scalar(sh: SizeHint, x: usize) -> SizeHint {
 /// ```
 #[inline]
 pub fn mul(a: SizeHint, b: SizeHint) -> SizeHint {
-    let low = a.0.checked_mul(b.0).unwrap_or(usize::MAX);
+    let low = a.0.saturating_mul(b.0);
     let hi = match (a.1, b.1) {
         (Some(x), Some(y)) => x.checked_mul(y),
         (Some(0), None) | (None, Some(0)) => Some(0),
diff --git a/src/sources.rs b/src/sources.rs
index 270b6ca37..5bb6afe4a 100644
--- a/src/sources.rs
+++ b/src/sources.rs
@@ -7,7 +7,7 @@ use std::mem;
 
 /// See [`repeat_call`](../fn.repeat_call.html) for more information.
 #[derive(Clone)]
-#[deprecated(note="Use std repeat_with() instead", since="0.8")]
+#[deprecated(note="Use std repeat_with() instead", since="0.8.0")]
 pub struct RepeatCall<F> {
     f: F,
 }
@@ -39,7 +39,7 @@ impl<F> fmt::Debug for RepeatCall<F>
 ///     vec![1, 1, 1, 1, 1]
 /// );
 /// ```
-#[deprecated(note="Use std repeat_with() instead", since="0.8")]
+#[deprecated(note="Use std repeat_with() instead", since="0.8.0")]
 pub fn repeat_call<F, A>(function: F) -> RepeatCall<F>
     where F: FnMut() -> A
 {
diff --git a/src/tuple_impl.rs b/src/tuple_impl.rs
index 4388e71e3..784830645 100644
--- a/src/tuple_impl.rs
+++ b/src/tuple_impl.rs
@@ -57,12 +57,12 @@ impl<T> Iterator for TupleBuffer<T>
 
     fn size_hint(&self) -> (usize, Option<usize>) {
         let buffer = &self.buf.as_ref()[self.cur..];
-        let len = if buffer.len() == 0 {
+        let len = if buffer.is_empty() {
             0
         } else {
             buffer.iter()
                   .position(|x| x.is_none())
-                  .unwrap_or(buffer.len())
+                  .unwrap_or_else(|| buffer.len())
         };
         (len, Some(len))
     }
@@ -212,7 +212,7 @@ pub fn circular_tuple_windows<I, T>(iter: I) -> CircularTupleWindows<I, T>
     let iter = tuple_windows(iter.cycle()).take(len);
 
     CircularTupleWindows {
-        iter: iter,
+        iter,
         phantom_data: PhantomData{}
     }
 }