diff --git a/i18n/iconv.rs b/i18n/iconv.rs
index 4ddae8d8..6cab1b23 100644
--- a/i18n/iconv.rs
+++ b/i18n/iconv.rs
@@ -147,9 +147,9 @@ impl<R: Read> IntoIterator for CircularBuffer<R> {
     }
 }
 
+#[allow(non_camel_case_types, clippy::upper_case_acronyms)]
 #[derive(EnumString, EnumIter, Debug, PartialEq, Display)]
 #[strum(serialize_all = "SCREAMING-KEBAB-CASE")]
-#[allow(non_camel_case_types)]
 enum Encodings {
     ASCII,
     UTF_8,
@@ -427,7 +427,7 @@ fn charmap_conversion(
     for byte in input {
         buffer.push(byte);
         let mut found = false;
-        for (_, entry) in &from.entries {
+        for entry in from.entries.values() {
             if buffer.starts_with(&entry.encoding) {
                 if let Some(to_entry) = to
                     .entries
diff --git a/i18n/iconv_lib/ascii.rs b/i18n/iconv_lib/ascii.rs
index 12270308..675cf538 100644
--- a/i18n/iconv_lib/ascii.rs
+++ b/i18n/iconv_lib/ascii.rs
@@ -17,8 +17,8 @@ pub fn to_ucs4<I: Iterator<Item = u8> + 'static>(
 ) -> Box<dyn Iterator<Item = u32>> {
     let mut position = 0;
 
-    let iter = std::iter::from_fn(move || {
-        while let Some(code_point) = input.next() {
+    let iter = iter::from_fn(move || {
+        for code_point in input.by_ref() {
             position += 1;
             if code_point <= 127 {
                 return Some(code_point as u32);
@@ -43,8 +43,9 @@ pub fn from_ucs4<I: Iterator<Item = u32> + 'static>(
     suppress_error: bool,
 ) -> Box<dyn Iterator<Item = u8>> {
     let mut position = 0;
+
     let iter = iter::from_fn(move || {
-        while let Some(code_point) = input.next() {
+        for code_point in input.by_ref() {
             position += 1;
             if code_point <= 127 {
                 return Some(code_point as u8);
diff --git a/i18n/iconv_lib/utf_8.rs b/i18n/iconv_lib/utf_8.rs
index a65ee364..17e1543e 100644
--- a/i18n/iconv_lib/utf_8.rs
+++ b/i18n/iconv_lib/utf_8.rs
@@ -33,7 +33,7 @@ pub fn to_ucs4<I: Iterator<Item = u8> + 'static>(
                 return Some(code_point);
 
             // 2 bytes
-            } else if byte >= 0xC0 && byte <= 0xDF {
+            } else if (0xC0..=0xDF).contains(&byte) {
                 if buffer.len() < 2 {
                     let add_bytes = input.by_ref().take(2 - buffer.len()).collect::<Vec<_>>();
                     buffer.extend(add_bytes);
@@ -76,7 +76,7 @@ pub fn to_ucs4<I: Iterator<Item = u8> + 'static>(
                 return Some(code_point);
 
             // 3 bytes
-            } else if byte >= 0xE0 && byte <= 0xEF {
+            } else if (0xE0..=0xEF).contains(&byte) {
                 if buffer.len() < 3 {
                     let add_bytes = input.by_ref().take(3 - buffer.len()).collect::<Vec<_>>();
                     buffer.extend(add_bytes);
@@ -121,7 +121,7 @@ pub fn to_ucs4<I: Iterator<Item = u8> + 'static>(
                 return Some(code_point);
 
             // 4 bytes
-            } else if byte >= 0xF0 && byte <= 0xF4 {
+            } else if (0xF0..=0xF4).contains(&byte) {
                 if buffer.len() < 4 {
                     let add_bytes = input.by_ref().take(4 - buffer.len()).collect::<Vec<_>>();
                     buffer.extend(add_bytes);
@@ -155,7 +155,7 @@ pub fn to_ucs4<I: Iterator<Item = u8> + 'static>(
                     | ((buffer[1] as u32 & 0x3F) << 12)
                     | ((buffer[2] as u32 & 0x3F) << 6)
                     | (buffer[3] as u32 & 0x3F);
-                if code_point > 0x10FFFF || code_point < 0x10000 {
+                if !(0x10000..=0x10FFFF).contains(&code_point) {
                     if omit_invalid {
                         buffer.drain(0..4);
                         continue;