Use an associated const for the element names

epp-client-macros/src/lib.rs

@@ -39,9 +39,7 @@ fn element_name_macro(ast: &syn::DeriveInput) -> TokenStream {
 
     let implement = quote! {
         impl #impl_generics ElementName for #name #type_generics {
-            fn element_name(&self) -> &'static str {
-                #elem_name
-            }
+            const ELEMENT: &'static str = #elem_name;
         }
     };
     implement.into()

epp-client/src/epp/object.rs

@@ -44,7 +44,7 @@ impl StringValueTrait for String {
 
 /// Trait to set correct value for xml tags when tags are being generated from generic types
 pub trait ElementName {
-    fn element_name(&self) -> &'static str;
+    const ELEMENT: &'static str;
 }
 
 #[derive(Serialize, Deserialize, Debug, PartialEq, ElementName)]
@@ -72,11 +72,9 @@ impl<T: ElementName + Serialize> Serialize for EppObject<T> {
     where
         S: Serializer,
     {
-        let data_name = self.data.element_name();
-
         let mut state = serializer.serialize_struct("epp", 4)?;
         state.serialize_field("xmlns", &self.xmlns)?;
-        state.serialize_field(data_name, &self.data)?;
+        state.serialize_field(T::ELEMENT, &self.data)?;
         state.end()
     }
 }
@@ -115,10 +113,8 @@ impl<E: ElementName + Serialize> Serialize for Extension<E> {
     where
         S: Serializer,
     {
-        let data_name = self.data.element_name();
-
         let mut state = serializer.serialize_struct("extension", 1)?;
-        state.serialize_field(data_name, &self.data)?;
+        state.serialize_field(E::ELEMENT, &self.data)?;
         state.end()
     }
 }

epp-client/src/epp/request.rs

@@ -48,9 +48,8 @@ impl<T: ElementName + Serialize, E: ElementName + Serialize> Serialize
     where
         S: Serializer,
     {
-        let command_name = self.command.element_name();
         let mut state = serializer.serialize_struct("command", 3)?;
-        state.serialize_field(command_name, &self.command)?;
+        state.serialize_field(T::ELEMENT, &self.command)?;
         state.serialize_field("extension", &self.extension)?;
         state.serialize_field("clTRID", &self.client_tr_id)?;
         state.end()