Fix various clippy warnings in the serde code

gstreamer/src/caps_serde.rs

@@ -117,10 +117,10 @@ impl<'de> Visitor<'de> for CapsItemVisitor {
     fn visit_seq<A: SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
         let structure = seq
             .next_element::<Structure>()?
-            .ok_or(de::Error::custom("Expected a `Structure` for `Caps` item"))?;
+            .ok_or_else(|| de::Error::custom("Expected a `Structure` for `Caps` item"))?;
         let features_option =
             seq.next_element::<Option<CapsFeatures>>()?
-                .ok_or(de::Error::custom(
+                .ok_or_else(|| de::Error::custom(
                     "Expected an `Option<CapsFeature>` for `Caps` item",
                 ))?;
 

gstreamer/src/clock_time_serde.rs

@@ -35,7 +35,7 @@ impl<'de> Visitor<'de> for ClockTimeVisitor {
     where
         D: Deserializer<'de>,
     {
-        u64::deserialize(deserializer).map(|value| ClockTime::from_nseconds(value))
+        u64::deserialize(deserializer).map(ClockTime::from_nseconds)
     }
 
     fn visit_none<E: de::Error>(self) -> Result<Self::Value, E> {

gstreamer/src/format_serde.rs

@@ -24,7 +24,7 @@ macro_rules! impl_ser_de(
 
         impl<'de> Deserialize<'de> for $t {
             fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error> {
-                Option::<u64>::deserialize(deserializer).map(|value| $t(value))
+                Option::<u64>::deserialize(deserializer).map($t)
             }
         }
     }

gstreamer/src/structure_serde.rs

@@ -91,12 +91,12 @@ impl<'de> Visitor<'de> for FieldVisitor {
     fn visit_seq<A: SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
         let name = seq
             .next_element::<String>()?
-            .ok_or(de::Error::custom("Expected a value for `Value` name"))?;
+            .ok_or_else(|| de::Error::custom("Expected a value for `Value` name"))?;
         let type_name = seq
             .next_element::<String>()?
-            .ok_or(de::Error::custom("Expected a value for `Value` type"))?;
+            .ok_or_else(|| de::Error::custom("Expected a value for `Value` type"))?;
         let send_value = de_send_value!(type_name, seq)?
-            .ok_or(de::Error::custom("Expected a value for `Value`"))?;
+            .ok_or_else(|| de::Error::custom("Expected a value for `Value`"))?;
         Ok(FieldDe(name, send_value))
     }
 }
@@ -146,10 +146,10 @@ impl<'de> Visitor<'de> for StructureVisitor {
     fn visit_seq<A: SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
         let name = seq
             .next_element::<String>()?
-            .ok_or(de::Error::custom("Expected a name for the `Structure`"))?;
+            .ok_or_else(|| de::Error::custom("Expected a name for the `Structure`"))?;
         let mut structure = Structure::new_empty(&name);
         seq.next_element_seed(FieldsDe(structure.as_mut()))?
-            .ok_or(de::Error::custom("Expected a sequence of `Field`s"))?;
+            .ok_or_else(|| de::Error::custom("Expected a sequence of `Field`s"))?;
 
         Ok(structure)
     }

gstreamer/src/tags_serde.rs

@@ -44,9 +44,11 @@ impl<'a> TagValuesSer<'a> {
 
 impl<'a> Serialize for TagValuesSer<'a> {
     fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
+        use std::ops::DerefMut;
+
         let mut tag_iter = self.0.borrow_mut();
         let mut seq = serializer.serialize_seq(tag_iter.size_hint().1)?;
-        while let Some(value) = tag_iter.next() {
+        for value in tag_iter.deref_mut() {
             match value.type_() {
                 glib::Type::F64 => ser_tag!(value, seq, f64),
                 glib::Type::String => ser_tag!(value, seq, String),
@@ -202,9 +204,9 @@ impl<'de, 'a> Visitor<'de> for TagValuesTupleVisitor<'a> {
         let name = seq
             .next_element::<String>()
             .map_err(|err| de::Error::custom(format!("Error reading Tag name. {:?}", err)))?
-            .ok_or(de::Error::custom("Expected a name for the `Tag` name"))?;
+            .ok_or_else(|| de::Error::custom("Expected a name for the `Tag` name"))?;
         seq.next_element_seed(TagValues(name.as_str(), self.0))?
-            .ok_or(de::Error::custom("Expected a seq of values for the `Tag`"))
+            .ok_or_else(|| de::Error::custom("Expected a seq of values for the `Tag`"))
     }
 }
 

gstreamer/src/value_serde.rs

@@ -115,6 +115,7 @@ macro_rules! ser_value (
     );
 );
 
+#[repr(C)]
 pub(crate) struct SendValue(glib::SendValue);
 impl SendValue {
     pub(crate) fn from(send_value: glib::SendValue) -> Self {
@@ -144,9 +145,7 @@ macro_rules! impl_ser_send_value_collection (
         impl<'a> Serialize for $t<'a> {
             fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error> {
                 let send_value_vec = unsafe {
-                    mem::transmute::<&[glib::SendValue], &[SendValue]>(
+                    &*(self.as_slice() as *const [glib::SendValue] as *const [SendValue])
-                        self.as_slice()
-                    )
                 };
                 send_value_vec.serialize(serializer)
             }
@@ -232,9 +231,9 @@ impl<'de> Visitor<'de> for SendValueVisitor {
     fn visit_seq<A: SeqAccess<'de>>(self, mut seq: A) -> Result<Self::Value, A::Error> {
         let type_name = seq
             .next_element::<String>()?
-            .ok_or(de::Error::custom("Expected a value for `Value` type"))?;
+            .ok_or_else(|| de::Error::custom("Expected a value for `Value` type"))?;
         let send_value = de_send_value!(type_name, seq)?
-            .ok_or(de::Error::custom("Expected a value for `Value`"))?;
+            .ok_or_else(|| de::Error::custom("Expected a value for `Value`"))?;
         Ok(send_value)
     }
 }