Fix new warnings from nightly Rust

src/dictionary.rs

@@ -7,7 +7,6 @@
 use indexmap::{map, IndexMap};
 use std::{
     fmt::{self, Debug},
-    iter::FromIterator,
     ops,
 };
 
@@ -67,7 +66,7 @@ impl Dictionary {
     /// in the dictionary.
     #[inline]
     pub fn remove(&mut self, key: &str) -> Option<Value> {
-        self.map.remove(key)
+        self.map.swap_remove(key)
     }
 
     /// Scan through each key-value pair in the map and keep those where the
@@ -540,7 +539,7 @@ impl<'a> OccupiedEntry<'a> {
     /// ```
     #[inline]
     pub fn remove(self) -> Value {
-        self.occupied.remove()
+        self.occupied.swap_remove()
     }
 }
 

src/error.rs

@@ -61,11 +61,17 @@ pub(crate) enum ErrorKind {
     InfiniteOrNanDate,
     InvalidUtf8String,
     InvalidUtf16String,
-    UnknownObjectType(u8),
+    UnknownObjectType(
+        // Used by the `Debug` implementation.
+        #[allow(dead_code)] u8,
+    ),
 
     Io(io::Error),
     #[cfg(feature = "serde")]
-    Serde(String),
+    Serde(
+        // Used by the `Debug` implementation.
+        #[allow(dead_code)] String,
+    ),
 }
 
 #[derive(Debug, Clone, Copy)]

src/stream/binary_reader.rs

@@ -412,7 +412,6 @@ mod tests {
     use std::fs::File;
 
     use super::*;
-    use crate::{stream::Event, Uid};
 
     #[test]
     fn streaming_parser() {

src/stream/xml_reader.rs

@@ -211,7 +211,7 @@ mod tests {
     use std::fs::File;
 
     use super::*;
-    use crate::stream::Event::{self, *};
+    use crate::stream::Event::*;
 
     #[test]
     fn streaming_parser() {

src/value.rs

@@ -770,7 +770,7 @@ mod tests {
     use std::time::SystemTime;
 
     use super::*;
-    use crate::{stream::Event::*, Date, Dictionary, Value};
+    use crate::{stream::Event::*, Date};
 
     #[test]
     fn value_accessors() {