[Rust] [Axum] Fix clippy warning: to_string_trait_impl (#17995)

* [Rust] [Axum] Fix clippy warning

* Using Display trait

modules/openapi-generator/src/main/resources/rust-axum/models.mustache

@@ -387,9 +387,9 @@ impl std::convert::From<{{{dataType}}}> for {{{classname}}} {
 }
 {{#vendorExtensions.x-is-string}}
 
-impl std::string::ToString for {{{classname}}} {
-    fn to_string(&self) -> String {
-       self.0.to_string()
+impl std::fmt::Display for {{{classname}}} {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+       write!(f, "{:?}", self.0)
     }
 }
 
@@ -424,10 +424,10 @@ impl std::ops::DerefMut for {{{classname}}} {
 /// Converts the {{{classname}}} value to the Query Parameters representation (style=form, explode=false)
 /// specified in https://swagger.io/docs/specification/serialization/
 /// Should be implemented in a serde serializer
-impl ::std::string::ToString for {{{classname}}} {
-    fn to_string(&self) -> String {
+impl std::fmt::Display for {{{classname}}} {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         // Skipping additionalProperties in query parameter serialization
-        "".to_string()
+        write!(f, "")
     }
 }
 
@@ -517,9 +517,9 @@ impl std::ops::DerefMut for {{{classname}}} {
 /// Converts the {{{classname}}} value to the Query Parameters representation (style=form, explode=false)
 /// specified in https://swagger.io/docs/specification/serialization/
 /// Should be implemented in a serde serializer
-impl std::string::ToString for {{{classname}}} {
-    fn to_string(&self) -> String {
-        self.iter().map(|x| x.to_string()).collect::<Vec<_>>().join(",")
+impl std::fmt::Display for {{{classname}}} {
+   fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+       write!(f, "{}", self.iter().map(|x| x.to_string()).collect::<Vec<_>>().join(","))
     }
 }
 
@@ -726,8 +726,8 @@ impl {{{classname}}} {
 /// Converts the {{{classname}}} value to the Query Parameters representation (style=form, explode=false)
 /// specified in https://swagger.io/docs/specification/serialization/
 /// Should be implemented in a serde serializer
-impl std::string::ToString for {{{classname}}} {
-    fn to_string(&self) -> String {
+impl std::fmt::Display for {{{classname}}} {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let params: Vec<Option<String>> = vec![
 {{#vars}}
 {{#isByteArray}}
@@ -789,7 +789,7 @@ impl std::string::ToString for {{{classname}}} {
 {{/vars}}
         ];
 
-        params.into_iter().flatten().collect::<Vec<_>>().join(",")
+        write!(f, "{}", params.into_iter().flatten().collect::<Vec<_>>().join(","))
     }
 }
 

samples/server/petstore/rust-axum/output/multipart-v3/.openapi-generator/VERSION

@@ -1 +1 @@
-7.3.0-SNAPSHOT
+7.4.0-SNAPSHOT

samples/server/petstore/rust-axum/output/multipart-v3/src/models.rs

@@ -36,8 +36,8 @@ impl MultipartRelatedRequest {
 /// Converts the MultipartRelatedRequest value to the Query Parameters representation (style=form, explode=false)
 /// specified in https://swagger.io/docs/specification/serialization/
 /// Should be implemented in a serde serializer
-impl std::string::ToString for MultipartRelatedRequest {
-    fn to_string(&self) -> String {
+impl std::fmt::Display for MultipartRelatedRequest {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let params: Vec<Option<String>> = vec![
             // Skipping object_field in query parameter serialization
 
@@ -49,7 +49,11 @@ impl std::string::ToString for MultipartRelatedRequest {
 
         ];
 
-        params.into_iter().flatten().collect::<Vec<_>>().join(",")
+        write!(
+            f,
+            "{}",
+            params.into_iter().flatten().collect::<Vec<_>>().join(",")
+        )
     }
 }
 
@@ -184,8 +188,8 @@ impl MultipartRequestObjectField {
 /// Converts the MultipartRequestObjectField value to the Query Parameters representation (style=form, explode=false)
 /// specified in https://swagger.io/docs/specification/serialization/
 /// Should be implemented in a serde serializer
-impl std::string::ToString for MultipartRequestObjectField {
-    fn to_string(&self) -> String {
+impl std::fmt::Display for MultipartRequestObjectField {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let params: Vec<Option<String>> = vec![
             Some("field_a".to_string()),
             Some(self.field_a.to_string()),
@@ -202,7 +206,11 @@ impl std::string::ToString for MultipartRequestObjectField {
             }),
         ];
 
-        params.into_iter().flatten().collect::<Vec<_>>().join(",")
+        write!(
+            f,
+            "{}",
+            params.into_iter().flatten().collect::<Vec<_>>().join(",")
+        )
     }
 }
 
@@ -333,8 +341,8 @@ impl MultipleIdenticalMimeTypesPostRequest {
 /// Converts the MultipleIdenticalMimeTypesPostRequest value to the Query Parameters representation (style=form, explode=false)
 /// specified in https://swagger.io/docs/specification/serialization/
 /// Should be implemented in a serde serializer
-impl std::string::ToString for MultipleIdenticalMimeTypesPostRequest {
-    fn to_string(&self) -> String {
+impl std::fmt::Display for MultipleIdenticalMimeTypesPostRequest {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let params: Vec<Option<String>> = vec![
             // Skipping binary1 in query parameter serialization
             // Skipping binary1 in query parameter serialization
@@ -344,7 +352,11 @@ impl std::string::ToString for MultipleIdenticalMimeTypesPostRequest {
 
         ];
 
-        params.into_iter().flatten().collect::<Vec<_>>().join(",")
+        write!(
+            f,
+            "{}",
+            params.into_iter().flatten().collect::<Vec<_>>().join(",")
+        )
     }
 }
 

samples/server/petstore/rust-axum/output/openapi-v3/.openapi-generator/VERSION

@@ -1 +1 @@
-7.3.0-SNAPSHOT
+7.4.0-SNAPSHOT