address new clippy lints

actix-web/src/middleware/err_handlers.rs

@@ -270,8 +270,8 @@ impl<B> ErrorHandlers<B> {
         handlers
             .get(status)
             .map(|h| h.as_ref())
-            .or_else(|| status.is_client_error().then(|| default_client).flatten())
+            .or_else(|| status.is_client_error().then_some(default_client).flatten())
-            .or_else(|| status.is_server_error().then(|| default_server).flatten())
+            .or_else(|| status.is_server_error().then_some(default_server).flatten())
     }
 }
 

actix-web/src/middleware/normalize.rs

@@ -15,11 +15,12 @@ use crate::{
 ///
 /// The default is `TrailingSlash::Trim`.
 #[non_exhaustive]
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Default)]
 pub enum TrailingSlash {
     /// Trim trailing slashes from the end of the path.
     ///
     /// Using this will require all routes to omit trailing slashes for them to be accessible.
+    #[default]
     Trim,
 
     /// Only merge any present multiple trailing slashes.
@@ -33,12 +34,6 @@ pub enum TrailingSlash {
     Always,
 }
 
-impl Default for TrailingSlash {
-    fn default() -> Self {
-        TrailingSlash::Trim
-    }
-}
-
 /// Middleware for normalizing a request's path so that routes can be matched more flexibly.
 ///
 /// # Normalization Steps

actix-web/src/request_data.rs

@@ -27,7 +27,6 @@ use crate::{
 /// # Examples
 /// ```no_run
 /// # use actix_web::{web, HttpResponse, HttpRequest, Responder, HttpMessage as _};
-///
 /// #[derive(Debug, Clone, PartialEq)]
 /// struct FlagFromMiddleware(String);
 ///

actix-web/src/rmap.rs

@@ -136,7 +136,7 @@ impl ResourceMap {
             .root_rmap_fn(String::with_capacity(AVG_PATH_LEN), |mut acc, node| {
                 node.pattern
                     .resource_path_from_iter(&mut acc, &mut elements)
-                    .then(|| acc)
+                    .then_some(acc)
             })
             .ok_or(UrlGenerationError::NotEnoughElements)?;
 
@@ -149,7 +149,7 @@ impl ResourceMap {
             // external resource; third slash would be the root slash in the path
             let third_slash_index = path
                 .char_indices()
-                .filter_map(|(i, c)| (c == '/').then(|| i))
+                .filter_map(|(i, c)| (c == '/').then_some(i))
                 .nth(2)
                 .unwrap_or(path.len());