diff --git a/src/header/bits_time/mod.rs b/src/header/bits_time/mod.rs
index c564826efc..3be2fffc83 100644
--- a/src/header/bits_time/mod.rs
+++ b/src/header/bits_time/mod.rs
@@ -16,12 +16,8 @@ impl timespec {
 
     /// similar logic with timeradd
     pub fn add(base: timespec, interval: timespec) -> Option<timespec> {
-        let Some(delta_sec) = base.tv_sec.checked_add(interval.tv_sec) else {
-            return None;
-        };
-        let Some(delta_nsec) = base.tv_nsec.checked_add(interval.tv_nsec) else {
-            return None;
-        };
+        let delta_sec = base.tv_sec.checked_add(interval.tv_sec)?;
+        let delta_nsec = base.tv_nsec.checked_add(interval.tv_nsec)?;
 
         if delta_sec < 0 || delta_nsec < 0 {
             return None;
@@ -34,12 +30,8 @@ impl timespec {
     }
     /// similar logic with timersub
     pub fn subtract(later: timespec, earlier: timespec) -> Option<timespec> {
-        let Some(delta_sec) = later.tv_sec.checked_sub(earlier.tv_sec) else {
-            return None;
-        };
-        let Some(delta_nsec) = later.tv_nsec.checked_sub(earlier.tv_nsec) else {
-            return None;
-        };
+        let delta_sec = later.tv_sec.checked_sub(earlier.tv_sec)?;
+        let delta_nsec = later.tv_nsec.checked_sub(earlier.tv_nsec)?;
 
         let time = if delta_nsec < 0 {
             let roundup_sec = -delta_nsec / NANOSECONDS + 1;
@@ -63,7 +55,7 @@ impl timespec {
         Some(time)
     }
     pub fn is_default(&self) -> bool {
-        return self.tv_nsec == 0 && self.tv_sec == 0;
+        self.tv_nsec == 0 && self.tv_sec == 0
     }
 }
 
diff --git a/src/header/crypt/blowfish.rs b/src/header/crypt/blowfish.rs
index 3d24325d90..54e9fe1082 100644
--- a/src/header/crypt/blowfish.rs
+++ b/src/header/crypt/blowfish.rs
@@ -73,7 +73,7 @@ pub fn crypt_blowfish(passw: &str, setting: &str) -> Option<String> {
 
         // We only consider the first 72 chars; truncate if necessary.
         let passw_t = if vec.len() > 72 { &vec[..72] } else { &vec };
-        let passw: &[c_uchar] = &passw_t;
+        let passw: &[c_uchar] = passw_t;
         let setting = setting.as_bytes();
         let mut output = vec![0; BHASH_OUTPUT_SIZE + 1];
 
diff --git a/src/header/crypt/pbkdf2.rs b/src/header/crypt/pbkdf2.rs
index 43e0e24d53..9a614873e6 100644
--- a/src/header/crypt/pbkdf2.rs
+++ b/src/header/crypt/pbkdf2.rs
@@ -1,7 +1,7 @@
 use super::gen_salt;
 use alloc::string::{String, ToString};
 use base64ct::{Base64Bcrypt, Encoding};
-use core::{str, u32};
+use core::str;
 use pbkdf2::pbkdf2_hmac;
 use sha2::Sha256;
 
@@ -42,7 +42,7 @@ pub fn crypt_pbkdf2(passw: &str, setting: &str) -> Option<String> {
             return None;
         }
 
-        let actual_salt = if salt.len() > 0 {
+        let actual_salt = if !salt.is_empty() {
             salt.to_string()
         } else {
             gen_salt()?
diff --git a/src/header/crypt/scrypt.rs b/src/header/crypt/scrypt.rs
index dde4bc348d..334d9dfdb4 100644
--- a/src/header/crypt/scrypt.rs
+++ b/src/header/crypt/scrypt.rs
@@ -2,7 +2,7 @@ use super::gen_salt;
 use crate::platform::types::{c_uchar, c_uint};
 use alloc::string::{String, ToString};
 use base64ct::{Base64Bcrypt, Encoding};
-use core::{str, u32};
+use core::str;
 use scrypt::{Params, scrypt};
 
 /// Map for encoding and decoding
@@ -29,14 +29,12 @@ fn dencode_uint(value: &str) -> Option<c_uint> {
         return None;
     }
 
-    let result = value
+    value
         .chars()
         .enumerate()
         .try_fold(0 as c_uint, |acc, (i, c)| {
             acc.checked_add((to_digit(c, 30)? as c_uint) << (i * 6))
-        });
-
-    Some(result?)
+        })
 }
 
 /// Reads settings for password encryption
@@ -54,7 +52,7 @@ fn read_setting(setting: &str) -> Option<(c_uchar, c_uint, c_uint, String)> {
     let p = dencode_uint(&setting[6..11])?;
 
     let salt = &setting[11..];
-    let actual_salt = if salt.len() > 0 {
+    let actual_salt = if !salt.is_empty() {
         salt.to_string()
     } else {
         gen_salt()?
diff --git a/src/header/ctype/mod.rs b/src/header/ctype/mod.rs
index 6691357474..3d8da3cffe 100644
--- a/src/header/ctype/mod.rs
+++ b/src/header/ctype/mod.rs
@@ -53,7 +53,7 @@ pub extern "C" fn isblank_l(c: c_int, _loc: locale_t) -> c_int {
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/iscntrl.html>.
 #[unsafe(no_mangle)]
 pub extern "C" fn iscntrl(c: c_int) -> c_int {
-    c_int::from((c >= 0x00 && c <= 0x1f) || c == 0x7f)
+    c_int::from((0x00..=0x1f).contains(&c) || c == 0x7f)
 }
 
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/iscntrl_l.html>.
@@ -77,7 +77,7 @@ pub extern "C" fn isdigit_l(c: c_int, _loc: locale_t) -> c_int {
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/isgraph.html>.
 #[unsafe(no_mangle)]
 pub extern "C" fn isgraph(c: c_int) -> c_int {
-    c_int::from(c >= 0x21 && c <= 0x7e)
+    c_int::from((0x21..=0x7e).contains(&c))
 }
 
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/isgraph_l.html>.
@@ -101,7 +101,7 @@ pub extern "C" fn islower_l(c: c_int, _loc: locale_t) -> c_int {
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/isprint.html>.
 #[unsafe(no_mangle)]
 pub extern "C" fn isprint(c: c_int) -> c_int {
-    c_int::from(c >= 0x20 && c < 0x7f)
+    c_int::from((0x20..0x7f).contains(&c))
 }
 
 /// See <https://pubs.opengroup.org/onlinepubs/9799919799/functions/isprint_l.html>.