4 files changed, 13 insertions, 14 deletions

diff --git a/src/builder.rs b/src/builder.rs
index f429ad4..4942b47 100644
--- a/src/builder.rs
+++ b/src/builder.rs
@@ -272,7 +272,7 @@ impl ConfigBuilder<AsyncState> {
     ///
     /// Calling this method does not invoke any I/O. [`Source`] is only saved in internal register for later use.
     #[must_use]
-    pub fn add_source<T>(mut self, source: T) -> ConfigBuilder<AsyncState>
+    pub fn add_source<T>(mut self, source: T) -> Self
     where
         T: Source + Send + Sync + 'static,
     {
@@ -284,7 +284,7 @@ impl ConfigBuilder<AsyncState> {
     ///
     /// Calling this method does not invoke any I/O. [`AsyncSource`] is only saved in internal register for later use.
     #[must_use]
-    pub fn add_async_source<T>(mut self, source: T) -> ConfigBuilder<AsyncState>
+    pub fn add_async_source<T>(mut self, source: T) -> Self
     where
         T: AsyncSource + Send + Sync + 'static,
     {
diff --git a/src/file/source/file.rs b/src/file/source/file.rs
index 9bd3ddd..a27c9d2 100644
--- a/src/file/source/file.rs
+++ b/src/file/source/file.rs
@@ -73,7 +73,7 @@ impl FileSourceFile {
             }
 
             None => {
-                for (format, extensions) in ALL_EXTENSIONS.iter() {
+                for format in ALL_EXTENSIONS.keys() {
                     for ext in format.extensions() {
                         filename.set_extension(ext);
 
diff --git a/src/lib.rs b/src/lib.rs
index 9088c26..589d2d5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -17,7 +17,6 @@
 //!
 //! See the [examples](https://github.com/mehcode/config-rs/tree/master/examples) for
 //! general usage information.
-#![allow(unused_variables)]
 #![allow(unknown_lints)]
 // #![warn(missing_docs)]
 
diff --git a/src/ser.rs b/src/ser.rs
index 3138488..72d5b01 100644
--- a/src/ser.rs
+++ b/src/ser.rs
@@ -231,7 +231,7 @@ impl<'a> ser::Serializer for &'a mut ConfigSerializer {
 
     fn serialize_tuple_variant(
         self,
-        name: &'static str,
+        _name: &'static str,
         _variant_index: u32,
         variant: &'static str,
         _len: usize,
@@ -253,7 +253,7 @@ impl<'a> ser::Serializer for &'a mut ConfigSerializer {
         _name: &'static str,
         _variant_index: u32,
         variant: &'static str,
-        len: usize,
+        _len: usize,
     ) -> Result<Self::SerializeStructVariant> {
         self.push_key(variant);
         Ok(self)
@@ -580,7 +580,7 @@ impl ser::SerializeSeq for StringKeySerializer {
     type Ok = String;
     type Error = ConfigError;
 
-    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+    fn serialize_element<T>(&mut self, _value: &T) -> Result<()>
     where
         T: ?Sized + ser::Serialize,
     {
@@ -596,7 +596,7 @@ impl ser::SerializeTuple for StringKeySerializer {
     type Ok = String;
     type Error = ConfigError;
 
-    fn serialize_element<T>(&mut self, value: &T) -> Result<()>
+    fn serialize_element<T>(&mut self, _value: &T) -> Result<()>
     where
         T: ?Sized + ser::Serialize,
     {
@@ -612,7 +612,7 @@ impl ser::SerializeTupleStruct for StringKeySerializer {
     type Ok = String;
     type Error = ConfigError;
 
-    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+    fn serialize_field<T>(&mut self, _value: &T) -> Result<()>
     where
         T: ?Sized + ser::Serialize,
     {
@@ -628,7 +628,7 @@ impl ser::SerializeTupleVariant for StringKeySerializer {
     type Ok = String;
     type Error = ConfigError;
 
-    fn serialize_field<T>(&mut self, value: &T) -> Result<()>
+    fn serialize_field<T>(&mut self, _value: &T) -> Result<()>
     where
         T: ?Sized + ser::Serialize,
     {
@@ -644,14 +644,14 @@ impl ser::SerializeMap for StringKeySerializer {
     type Ok = String;
     type Error = ConfigError;
 
-    fn serialize_key<T>(&mut self, key: &T) -> Result<()>
+    fn serialize_key<T>(&mut self, _key: &T) -> Result<()>
     where
         T: ?Sized + ser::Serialize,
     {
         unreachable!()
     }
 
-    fn serialize_value<T>(&mut self, value: &T) -> Result<()>
+    fn serialize_value<T>(&mut self, _value: &T) -> Result<()>
     where
         T: ?Sized + ser::Serialize,
     {
@@ -667,7 +667,7 @@ impl ser::SerializeStruct for StringKeySerializer {
     type Ok = String;
     type Error = ConfigError;
 
-    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+    fn serialize_field<T>(&mut self, _key: &'static str, _value: &T) -> Result<()>
     where
         T: ?Sized + ser::Serialize,
     {
@@ -683,7 +683,7 @@ impl ser::SerializeStructVariant for StringKeySerializer {
     type Ok = String;
     type Error = ConfigError;
 
-    fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
+    fn serialize_field<T>(&mut self, _key: &'static str, _value: &T) -> Result<()>
     where
         T: ?Sized + ser::Serialize,
     {