Address nits

serde/src/de/impls.rs

@@ -1024,8 +1024,6 @@ impl<T, E> Deserialize for Result<T, E> where T: Deserialize, E: Deserialize {
 
                     #[cfg(all(not(feature = "std"), not(feature = "collections")))]
                     fn visit_usize<E>(&mut self, value: usize) -> Result<Field, E> where E: Error {
-                        #[cfg(feature = "collections")]
-                        use collections::string::ToString;
                         match value {
                             0 => Ok(Field::Ok),
                             1 => Ok(Field::Err),

serde/src/ser/mod.rs

@@ -124,6 +124,7 @@ pub trait Serializer {
 
     /// Serializes a character. By default it serializes as bytes containing the UTF-8 encoding
     /// of the character.
+    #[inline]
     fn serialize_char(&mut self, v: char) -> Result<(), Self::Error> {
         self.serialize_bytes(::utils::encode_utf8(v).as_slice())
     }