Remove unit errors from String and Vec

Author: pvdrz

src/de.rs

@@ -318,7 +318,7 @@ impl<'de, const N: usize> Deserialize<'de> for String<N> {
             {
                 let mut s = String::new();
                 s.push_str(v)
-                    .map_err(|_| E::invalid_length(v.len(), &self))?;
+                    .ok_or_else(|| E::invalid_length(v.len(), &self))?;
                 Ok(s)
             }
 
@@ -332,7 +332,7 @@ impl<'de, const N: usize> Deserialize<'de> for String<N> {
                     core::str::from_utf8(v)
                         .map_err(|_| E::invalid_value(de::Unexpected::Bytes(v), &self))?,
                 )
-                .map_err(|_| E::invalid_length(v.len(), &self))?;
+                .ok_or_else(|| E::invalid_length(v.len(), &self))?;
 
                 Ok(s)
             }

src/string/mod.rs

@@ -164,7 +164,7 @@ impl<const N: usize> String<N> {
         for c in char::decode_utf16(v.iter().cloned()) {
             match c {
                 Ok(c) => {
-                    s.push(c).map_err(|_| FromUtf16Error::Capacity)?;
+                    s.push(c).ok_or(FromUtf16Error::Capacity)?;
                 }
                 Err(err) => {
                     return Err(FromUtf16Error::DecodeUtf16Error(err));
@@ -428,16 +428,15 @@ impl<S: VecStorage<u8> + ?Sized> StringInner<S> {
     ///
     /// let mut s: String<8> = String::try_from("foo")?;
     ///
-    /// assert!(s.push_str("bar").is_ok());
+    /// assert!(s.push_str("bar").is_some());
     ///
     /// assert_eq!("foobar", s);
     ///
-    /// assert!(s.push_str("tender").is_err());
+    /// assert!(s.push_str("tender").is_none());
     /// # Ok::<(), ()>(())
     /// ```
     #[inline]
-    #[allow(clippy::result_unit_err)]
-    pub fn push_str(&mut self, string: &str) -> Result<(), ()> {
+    pub fn push_str(&mut self, string: &str) -> Option<()> {
         self.vec.extend_from_slice(string.as_bytes())
     }
 
@@ -479,10 +478,9 @@ impl<S: VecStorage<u8> + ?Sized> StringInner<S> {
     /// # Ok::<(), ()>(())
     /// ```
     #[inline]
-    #[allow(clippy::result_unit_err)]
-    pub fn push(&mut self, c: char) -> Result<(), ()> {
+    pub fn push(&mut self, c: char) -> Option<()> {
         match c.len_utf8() {
-            1 => self.vec.push(c as u8).map_err(|_| {}),
+            1 => self.vec.push(c as u8).ok(),
             _ => self
                 .vec
                 .extend_from_slice(c.encode_utf8(&mut [0; 4]).as_bytes()),
@@ -633,7 +631,7 @@ impl<'a, const N: usize> TryFrom<&'a str> for String<N> {
     type Error = ();
     fn try_from(s: &'a str) -> Result<Self, Self::Error> {
         let mut new = Self::new();
-        new.push_str(s)?;
+        new.push_str(s).ok_or(())?;
         Ok(new)
     }
 }
@@ -643,7 +641,7 @@ impl<const N: usize> str::FromStr for String<N> {
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         let mut new = Self::new();
-        new.push_str(s)?;
+        new.push_str(s).ok_or(())?;
         Ok(new)
     }
 }
@@ -707,11 +705,11 @@ impl<S: VecStorage<u8> + ?Sized> hash::Hash for StringInner<S> {
 
 impl<S: VecStorage<u8> + ?Sized> fmt::Write for StringInner<S> {
     fn write_str(&mut self, s: &str) -> Result<(), fmt::Error> {
-        self.push_str(s).map_err(|_| fmt::Error)
+        self.push_str(s).ok_or(fmt::Error)
     }
 
     fn write_char(&mut self, c: char) -> Result<(), fmt::Error> {
-        self.push(c).map_err(|_| fmt::Error)
+        self.push(c).ok_or(fmt::Error)
     }
 }
 
@@ -1051,21 +1049,21 @@ mod tests {
     #[test]
     fn push_str() {
         let mut s: String<8> = String::try_from("foo").unwrap();
-        assert!(s.push_str("bar").is_ok());
+        assert!(s.push_str("bar").is_some());
         assert_eq!("foobar", s);
         assert_eq!(s, "foobar");
-        assert!(s.push_str("tender").is_err());
+        assert!(s.push_str("tender").is_none());
         assert_eq!("foobar", s);
         assert_eq!(s, "foobar");
     }
 
     #[test]
     fn push() {
         let mut s: String<6> = String::try_from("abc").unwrap();
-        assert!(s.push('1').is_ok());
-        assert!(s.push('2').is_ok());
-        assert!(s.push('3').is_ok());
-        assert!(s.push('4').is_err());
+        assert!(s.push('1').is_some());
+        assert!(s.push('2').is_some());
+        assert!(s.push('3').is_some());
+        assert!(s.push('4').is_none());
         assert!("abc123" == s.as_str());
     }
 

src/ufmt.rs

@@ -7,14 +7,14 @@ use ufmt_write::uWrite;
 impl<S: VecStorage<u8> + ?Sized> uWrite for StringInner<S> {
     type Error = ();
     fn write_str(&mut self, s: &str) -> Result<(), Self::Error> {
-        self.push_str(s)
+        self.push_str(s).ok_or_else(|| ())
     }
 }
 
 impl<S: VecStorage<u8> + ?Sized> uWrite for VecInner<u8, S> {
     type Error = ();
     fn write_str(&mut self, s: &str) -> Result<(), Self::Error> {
-        self.extend_from_slice(s.as_bytes())
+        self.extend_from_slice(s.as_bytes()).ok_or_else(|| ())
     }
 }
 

src/vec/mod.rs

@@ -192,14 +192,13 @@ impl<T, const N: usize> Vec<T, N> {
     /// let mut v: Vec<u8, 16> = Vec::new();
     /// v.extend_from_slice(&[1, 2, 3]).unwrap();
     /// ```
-    #[allow(clippy::result_unit_err)]
-    pub fn from_slice(other: &[T]) -> Result<Self, ()>
+    pub fn from_slice(other: &[T]) -> Option<Self>
     where
         T: Clone,
     {
         let mut v = Self::new();
         v.extend_from_slice(other)?;
-        Ok(v)
+        Some(v)
     }
 
     /// Constructs a new vector with a fixed capacity of `N`, initializing
@@ -517,28 +516,27 @@ impl<T, S: VecStorage<T> + ?Sized> VecInner<T, S> {
     /// vec.extend_from_slice(&[2, 3, 4]).unwrap();
     /// assert_eq!(*vec, [1, 2, 3, 4]);
     /// ```
-    #[allow(clippy::result_unit_err)]
-    pub fn extend_from_slice(&mut self, other: &[T]) -> Result<(), ()>
+    pub fn extend_from_slice(&mut self, other: &[T]) -> Option<()>
     where
         T: Clone,
     {
         pub fn extend_from_slice_inner<T>(
             len: &mut usize,
             buf: &mut [MaybeUninit<T>],
             other: &[T],
-        ) -> Result<(), ()>
+        ) -> Option<()>
         where
             T: Clone,
         {
             if *len + other.len() > buf.len() {
                 // won't fit in the `Vec`; don't modify anything and return an error
-                Err(())
+                None
             } else {
                 for elem in other {
                     unsafe { *buf.get_unchecked_mut(*len) = MaybeUninit::new(elem.clone()) }
                     *len += 1;
                 }
-                Ok(())
+                Some(())
             }
         }
 
@@ -627,13 +625,12 @@ impl<T, S: VecStorage<T> + ?Sized> VecInner<T, S> {
     /// new_len is less than len, the Vec is simply truncated.
     ///
     /// See also [`resize_default`](Self::resize_default).
-    #[allow(clippy::result_unit_err)]
-    pub fn resize(&mut self, new_len: usize, value: T) -> Result<(), ()>
+    pub fn resize(&mut self, new_len: usize, value: T) -> Option<()>
     where
         T: Clone,
     {
         if new_len > self.capacity() {
-            return Err(());
+            return None;
         }
 
         if new_len > self.len {
@@ -644,7 +641,7 @@ impl<T, S: VecStorage<T> + ?Sized> VecInner<T, S> {
             self.truncate(new_len);
         }
 
-        Ok(())
+        Some(())
     }
 
     /// Resizes the `Vec` in-place so that `len` is equal to `new_len`.
@@ -654,8 +651,7 @@ impl<T, S: VecStorage<T> + ?Sized> VecInner<T, S> {
     /// If `new_len` is less than `len`, the `Vec` is simply truncated.
     ///
     /// See also [`resize`](Self::resize).
-    #[allow(clippy::result_unit_err)]
-    pub fn resize_default(&mut self, new_len: usize) -> Result<(), ()>
+    pub fn resize_default(&mut self, new_len: usize) -> Option<()>
     where
         T: Clone + Default,
     {
@@ -1189,10 +1185,7 @@ where
 
 impl<S: VecStorage<u8> + ?Sized> fmt::Write for VecInner<u8, S> {
     fn write_str(&mut self, s: &str) -> fmt::Result {
-        match self.extend_from_slice(s.as_bytes()) {
-            Ok(()) => Ok(()),
-            Err(_) => Err(fmt::Error),
-        }
+        self.extend_from_slice(s.as_bytes()).ok_or(fmt::Error)
     }
 }
 
@@ -1215,7 +1208,7 @@ impl<'a, T: Clone, const N: usize> TryFrom<&'a [T]> for Vec<T, N> {
     type Error = ();
 
     fn try_from(slice: &'a [T]) -> Result<Self, Self::Error> {
-        Self::from_slice(slice)
+        Self::from_slice(slice).ok_or(())
     }
 }
 
@@ -1322,7 +1315,7 @@ where
                     self.vec.len() - self.next,
                 )
             };
-            vec.extend_from_slice(s).ok();
+            vec.extend_from_slice(s);
         }
 
         Self { vec, next: 0 }
@@ -1836,7 +1829,7 @@ mod tests {
 
         v.resize(0, 0).unwrap();
         v.resize(4, 0).unwrap();
-        v.resize(5, 0).expect_err("full");
+        assert!(v.resize(5, 0).is_none(), "full");
     }
 
     #[test]
@@ -1916,7 +1909,7 @@ mod tests {
         v.extend_from_slice(&[3]).unwrap();
         assert_eq!(v.len(), 3);
         assert_eq!(v.as_slice(), &[1, 2, 3]);
-        assert!(v.extend_from_slice(&[4, 5]).is_err());
+        assert!(v.extend_from_slice(&[4, 5]).is_none());
         assert_eq!(v.len(), 3);
         assert_eq!(v.as_slice(), &[1, 2, 3]);
     }
@@ -1929,7 +1922,7 @@ mod tests {
         assert_eq!(v.as_slice(), &[1, 2, 3]);
 
         // Slice too large
-        assert!(Vec::<u8, 2>::from_slice(&[1, 2, 3]).is_err());
+        assert!(Vec::<u8, 2>::from_slice(&[1, 2, 3]).is_none());
     }
 
     #[test]