diff --git a/src/adaptors/coalesce.rs b/src/adaptors/coalesce.rs
index 5ee321aad..1e3fa6054 100644
--- a/src/adaptors/coalesce.rs
+++ b/src/adaptors/coalesce.rs
@@ -74,9 +74,9 @@ where
     fn size_hint(&self) -> (usize, Option<usize>) {
         let (low, hi) = size_hint::add_scalar(
             self.iter.size_hint(),
-            matches!(self.last, Some(Some(_))) as usize,
+            usize::from(matches!(self.last, Some(Some(_)))),
         );
-        ((low > 0) as usize, hi)
+        (usize::from(low > 0), hi)
     }
 
     fn fold<Acc, FnAcc>(self, acc: Acc, mut fn_acc: FnAcc) -> Acc
diff --git a/src/adaptors/mod.rs b/src/adaptors/mod.rs
index 8fca0cfc5..b5c0d42b1 100644
--- a/src/adaptors/mod.rs
+++ b/src/adaptors/mod.rs
@@ -300,11 +300,11 @@ where
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
         // Not ExactSizeIterator because size may be larger than usize
-        size_hint::add_scalar(self.iter.size_hint(), self.top.is_some() as usize)
+        size_hint::add_scalar(self.iter.size_hint(), usize::from(self.top.is_some()))
     }
 
     fn count(self) -> usize {
-        self.iter.count() + (self.top.is_some() as usize)
+        self.iter.count() + usize::from(self.top.is_some())
     }
 
     fn last(self) -> Option<Self::Item> {
diff --git a/src/kmerge_impl.rs b/src/kmerge_impl.rs
index 2495cf782..e40f8077e 100644
--- a/src/kmerge_impl.rs
+++ b/src/kmerge_impl.rs
@@ -80,7 +80,7 @@ where
     while child + 1 < heap.len() {
         // pick the smaller of the two children
         // use arithmetic to avoid an unpredictable branch
-        child += less_than(&heap[child + 1], &heap[child]) as usize;
+        child += usize::from(less_than(&heap[child + 1], &heap[child]));
 
         // sift down is done if we are already in order
         if !less_than(&heap[child], &heap[pos]) {
diff --git a/src/unique_impl.rs b/src/unique_impl.rs
index 0f6397e48..eb8d32071 100644
--- a/src/unique_impl.rs
+++ b/src/unique_impl.rs
@@ -68,7 +68,7 @@ where
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
         let (low, hi) = self.iter.size_hint();
-        ((low > 0 && self.used.is_empty()) as usize, hi)
+        (usize::from(low > 0 && self.used.is_empty()), hi)
     }
 
     fn count(self) -> usize {
@@ -119,7 +119,7 @@ where
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
         let (low, hi) = self.iter.iter.size_hint();
-        ((low > 0 && self.iter.used.is_empty()) as usize, hi)
+        (usize::from(low > 0 && self.iter.used.is_empty()), hi)
     }
 
     fn count(self) -> usize {
diff --git a/tests/quick.rs b/tests/quick.rs
index 674848512..d3dd44ead 100644
--- a/tests/quick.rs
+++ b/tests/quick.rs
@@ -1064,7 +1064,7 @@ quickcheck! {
 
         let tup1 = |(_, b)| b;
         for &(ord, consume_now) in &order {
-            let iter = &mut [&mut chunks1, &mut chunks2][ord as usize];
+            let iter = &mut [&mut chunks1, &mut chunks2][usize::from(ord)];
             match iter.next() {
                 Some((_, gr)) => if consume_now {
                     for og in old_chunks.drain(..) {
@@ -1422,9 +1422,9 @@ quickcheck! {
     }
 
     fn correct_grouping_map_by_aggregate_modulo_key(a: Vec<u8>, modulo: u8) -> () {
-        let modulo = if modulo < 2 { 2 } else { modulo } as u64; // Avoid `% 0`
+        let modulo = u64::from(if modulo < 2 { 2 } else { modulo }); // Avoid `% 0`
         let lookup = a.iter()
-            .map(|&b| b as u64) // Avoid overflows
+            .map(|&b| u64::from(b)) // Avoid overflows
             .into_grouping_map_by(|i| i % modulo)
             .aggregate(|acc, &key, val| {
                 assert!(val % modulo == key);
@@ -1436,7 +1436,7 @@ quickcheck! {
             });
 
         let group_map_lookup = a.iter()
-            .map(|&b| b as u64)
+            .map(|&b| u64::from(b))
             .map(|i| (i % modulo, i))
             .into_group_map()
             .into_iter()
@@ -1456,7 +1456,7 @@ quickcheck! {
             assert_eq!(
                 lookup.get(&m).copied(),
                 a.iter()
-                    .map(|&b| b as u64)
+                    .map(|&b| u64::from(b))
                     .filter(|&val| val % modulo == m)
                     .fold(None, |acc, val| {
                         if val % (modulo - 1) == 0 {
@@ -1475,8 +1475,8 @@ quickcheck! {
             acc: u64,
         }
 
-        let modulo = if modulo == 0 { 1 } else { modulo } as u64; // Avoid `% 0`
-        let lookup = a.iter().map(|&b| b as u64) // Avoid overflows
+        let modulo = u64::from(if modulo == 0 { 1 } else { modulo }); // Avoid `% 0`
+        let lookup = a.iter().map(|&b| u64::from(b)) // Avoid overflows
             .into_grouping_map_by(|i| i % modulo)
             .fold_with(|_key, _val| Default::default(), |Accumulator { acc }, &key, val| {
                 assert!(val % modulo == key);
@@ -1485,7 +1485,7 @@ quickcheck! {
             });
 
         let group_map_lookup = a.iter()
-            .map(|&b| b as u64)
+            .map(|&b| u64::from(b))
             .map(|i| (i % modulo, i))
             .into_group_map()
             .into_iter()
@@ -1494,13 +1494,13 @@ quickcheck! {
         assert_eq!(lookup, group_map_lookup);
 
         for (&key, &Accumulator { acc: sum }) in lookup.iter() {
-            assert_eq!(sum, a.iter().map(|&b| b as u64).filter(|&val| val % modulo == key).sum::<u64>());
+            assert_eq!(sum, a.iter().map(|&b| u64::from(b)).filter(|&val| val % modulo == key).sum::<u64>());
         }
     }
 
     fn correct_grouping_map_by_fold_modulo_key(a: Vec<u8>, modulo: u8) -> () {
-        let modulo = if modulo == 0 { 1 } else { modulo } as u64; // Avoid `% 0`
-        let lookup = a.iter().map(|&b| b as u64) // Avoid overflows
+        let modulo = u64::from(if modulo == 0 { 1 } else { modulo }); // Avoid `% 0`
+        let lookup = a.iter().map(|&b| u64::from(b)) // Avoid overflows
             .into_grouping_map_by(|i| i % modulo)
             .fold(0u64, |acc, &key, val| {
                 assert!(val % modulo == key);
@@ -1508,7 +1508,7 @@ quickcheck! {
             });
 
         let group_map_lookup = a.iter()
-            .map(|&b| b as u64)
+            .map(|&b| u64::from(b))
             .map(|i| (i % modulo, i))
             .into_group_map()
             .into_iter()
@@ -1517,13 +1517,13 @@ quickcheck! {
         assert_eq!(lookup, group_map_lookup);
 
         for (&key, &sum) in lookup.iter() {
-            assert_eq!(sum, a.iter().map(|&b| b as u64).filter(|&val| val % modulo == key).sum::<u64>());
+            assert_eq!(sum, a.iter().map(|&b| u64::from(b)).filter(|&val| val % modulo == key).sum::<u64>());
         }
     }
 
     fn correct_grouping_map_by_reduce_modulo_key(a: Vec<u8>, modulo: u8) -> () {
-        let modulo = if modulo == 0 { 1 } else { modulo } as u64; // Avoid `% 0`
-        let lookup = a.iter().map(|&b| b as u64) // Avoid overflows
+        let modulo = u64::from(if modulo == 0 { 1 } else { modulo }); // Avoid `% 0`
+        let lookup = a.iter().map(|&b| u64::from(b)) // Avoid overflows
             .into_grouping_map_by(|i| i % modulo)
             .reduce(|acc, &key, val| {
                 assert!(val % modulo == key);
@@ -1531,7 +1531,7 @@ quickcheck! {
             });
 
         let group_map_lookup = a.iter()
-            .map(|&b| b as u64)
+            .map(|&b| u64::from(b))
             .map(|i| (i % modulo, i))
             .into_group_map()
             .into_iter()
@@ -1540,7 +1540,7 @@ quickcheck! {
         assert_eq!(lookup, group_map_lookup);
 
         for (&key, &sum) in lookup.iter() {
-            assert_eq!(sum, a.iter().map(|&b| b as u64).filter(|&val| val % modulo == key).sum::<u64>());
+            assert_eq!(sum, a.iter().map(|&b| u64::from(b)).filter(|&val| val % modulo == key).sum::<u64>());
         }
     }
 
@@ -1706,12 +1706,12 @@ quickcheck! {
     }
 
     fn correct_grouping_map_by_sum_modulo_key(a: Vec<u8>, modulo: u8) -> () {
-        let modulo = if modulo == 0 { 1 } else { modulo } as u64; // Avoid `% 0`
-        let lookup = a.iter().map(|&b| b as u64) // Avoid overflows
+        let modulo = u64::from(if modulo == 0 { 1 } else { modulo }); // Avoid `% 0`
+        let lookup = a.iter().map(|&b| u64::from(b)) // Avoid overflows
             .into_grouping_map_by(|i| i % modulo)
             .sum();
 
-        let group_map_lookup = a.iter().map(|&b| b as u64)
+        let group_map_lookup = a.iter().map(|&b| u64::from(b))
             .map(|i| (i % modulo, i))
             .into_group_map()
             .into_iter()
@@ -1720,17 +1720,17 @@ quickcheck! {
         assert_eq!(lookup, group_map_lookup);
 
         for (&key, &sum) in lookup.iter() {
-            assert_eq!(sum, a.iter().map(|&b| b as u64).filter(|&val| val % modulo == key).sum::<u64>());
+            assert_eq!(sum, a.iter().map(|&b| u64::from(b)).filter(|&val| val % modulo == key).sum::<u64>());
         }
     }
 
     fn correct_grouping_map_by_product_modulo_key(a: Vec<u8>, modulo: u8) -> () {
-        let modulo = Wrapping(if modulo == 0 { 1 } else { modulo } as u64); // Avoid `% 0`
-        let lookup = a.iter().map(|&b| Wrapping(b as u64)) // Avoid overflows
+        let modulo = Wrapping(u64::from(if modulo == 0 { 1 } else { modulo })); // Avoid `% 0`
+        let lookup = a.iter().map(|&b| Wrapping(u64::from(b))) // Avoid overflows
             .into_grouping_map_by(|i| i % modulo)
             .product();
 
-        let group_map_lookup = a.iter().map(|&b| Wrapping(b as u64))
+        let group_map_lookup = a.iter().map(|&b| Wrapping(u64::from(b)))
             .map(|i| (i % modulo, i))
             .into_group_map()
             .into_iter()
@@ -1742,7 +1742,7 @@ quickcheck! {
             assert_eq!(
                 prod,
                 a.iter()
-                    .map(|&b| Wrapping(b as u64))
+                    .map(|&b| Wrapping(u64::from(b)))
                     .filter(|&val| val % modulo == key)
                     .product::<Wrapping<u64>>()
             );
diff --git a/tests/test_std.rs b/tests/test_std.rs
index 0e4c11b80..dc0c163ba 100644
--- a/tests/test_std.rs
+++ b/tests/test_std.rs
@@ -496,7 +496,7 @@ qc::quickcheck! {
     fn k_smallest_range(n: i64, m: u16, k: u16) -> () {
         // u16 is used to constrain k and m to 0..2¹⁶,
         //  otherwise the test could use too much memory.
-        let (k, m) = (k as usize, m as u64);
+        let (k, m) = (k as usize, u64::from(m));
 
         let mut v: Vec<_> = (n..n.saturating_add(m as _)).collect();
         // Generate a random permutation of n..n+m
@@ -532,7 +532,7 @@ qc::quickcheck! {
     fn k_smallest_relaxed_range(n: i64, m: u16, k: u16) -> () {
         // u16 is used to constrain k and m to 0..2¹⁶,
         //  otherwise the test could use too much memory.
-        let (k, m) = (k as usize, m as u64);
+        let (k, m) = (k as usize, u64::from(m));
 
         let mut v: Vec<_> = (n..n.saturating_add(m as _)).collect();
         // Generate a random permutation of n..n+m