diff --git a/src/serde_json.rs b/src/serde_json.rs
index 4faaaea..4b078d9 100644
--- a/src/serde_json.rs
+++ b/src/serde_json.rs
@@ -1,5 +1,5 @@
 use core::str::Chars;
-use core::{error::Error, time::Duration};
+use core::{error::Error, fmt::Write, time::Duration};
 
 use alloc::boxed::Box;
 use alloc::collections::{BTreeMap, BTreeSet, LinkedList};
@@ -708,7 +708,7 @@ macro_rules! impl_ser_de_json_unsigned {
     ( $ ty: ident, $ max: expr) => {
         impl SerJson for $ty {
             fn ser_json(&self, _d: usize, s: &mut SerJsonState) {
-                s.out.push_str(&self.to_string());
+                _ = write!(s.out, "{self}");
             }
         }
 
@@ -726,7 +726,7 @@ macro_rules! impl_ser_de_json_signed {
     ( $ ty: ident, $ min: expr, $ max: expr) => {
         impl SerJson for $ty {
             fn ser_json(&self, _d: usize, s: &mut SerJsonState) {
-                s.out.push_str(&self.to_string());
+                _ = write!(s.out, "{self}");
             }
         }
 
@@ -745,7 +745,7 @@ macro_rules! impl_ser_de_json_float {
     ( $ ty: ident) => {
         impl SerJson for $ty {
             fn ser_json(&self, _d: usize, s: &mut SerJsonState) {
-                s.out.push_str(&format!("{self:?}"));
+                _ = write!(s.out, "{self:?}");
             }
         }
 
@@ -846,7 +846,6 @@ macro_rules! impl_ser_json_string {
                         '\r' => s.out += "\\r",
                         '\t' => s.out += "\\t",
                         _ if c.is_ascii_control() => {
-                            use core::fmt::Write as _;
                             let _ = write!(s.out, "\\u{:04x}", c as u32);
                         }
                         '\\' => s.out += "\\\\",
@@ -1310,10 +1309,9 @@ where
 impl SerJson for Duration {
     fn ser_json(&self, _d: usize, s: &mut SerJsonState) {
         s.out.push('{');
-        s.out.push_str(&format!("\"secs\":{}", self.as_secs()));
+        _ = write!(s.out, "\"secs\":{}", self.as_secs());
         if self.subsec_nanos() > 0 {
-            s.out
-                .push_str(&format!(",\"nanos\":{}", self.subsec_nanos()));
+            _ = write!(s.out, ",\"nanos\":{}", self.subsec_nanos());
         }
         s.out.push('}');
     }
diff --git a/src/serde_ron.rs b/src/serde_ron.rs
index d04df66..e9e44ec 100644
--- a/src/serde_ron.rs
+++ b/src/serde_ron.rs
@@ -1,5 +1,5 @@
 use core::str::Chars;
-use core::{error::Error, time::Duration};
+use core::{error::Error, fmt::Write, time::Duration};
 
 use alloc::boxed::Box;
 use alloc::collections::{BTreeMap, BTreeSet, LinkedList};
@@ -710,7 +710,7 @@ macro_rules! impl_ser_de_ron_unsigned {
     ( $ ty: ident, $ max: expr) => {
         impl SerRon for $ty {
             fn ser_ron(&self, _d: usize, s: &mut SerRonState) {
-                s.out.push_str(&self.to_string());
+                _ = write!(s.out, "{self}");
             }
         }
 
@@ -729,7 +729,7 @@ macro_rules! impl_ser_de_ron_signed {
     ( $ ty: ident, $ min: expr, $ max: expr) => {
         impl SerRon for $ty {
             fn ser_ron(&self, _d: usize, s: &mut SerRonState) {
-                s.out.push_str(&self.to_string());
+                _ = write!(s.out, "{self}");
             }
         }
 
@@ -748,7 +748,7 @@ macro_rules! impl_ser_de_ron_float {
     ( $ ty: ident) => {
         impl SerRon for $ty {
             fn ser_ron(&self, _d: usize, s: &mut SerRonState) {
-                s.out.push_str(&format!("{self:?}"));
+                _ = write!(s.out, "{self:?}");
             }
         }
 
@@ -1307,10 +1307,9 @@ where
 impl SerRon for Duration {
     fn ser_ron(&self, _d: usize, s: &mut SerRonState) {
         s.out.push('{');
-        s.out.push_str(&format!("\"secs\":{}", self.as_secs()));
+        _ = write!(s.out, "\"secs\":{}", self.as_secs());
         if self.subsec_nanos() > 0 {
-            s.out
-                .push_str(&format!(",\"nanos\":{}", self.subsec_nanos()));
+            _ = write!(s.out, ",\"nanos\":{}", self.subsec_nanos());
         }
         s.out.push('}');
     }
diff --git a/src/toml.rs b/src/toml.rs
index 73b70a9..41d44eb 100644
--- a/src/toml.rs
+++ b/src/toml.rs
@@ -12,7 +12,6 @@ macro_rules! ident_chars {
         '\u{41}'..='\u{5A}'
         | '\u{61}'..='\u{7A}'
         | '\u{30}'..='\u{39}'
-        | '\u{2D}'
         | '\u{5F}'
         | '\u{B2}'
         | '\u{B3}'