diff --git a/src/api/comment.rs b/src/api/comment.rs
index 2d0d66e..a0ea831 100644
--- a/src/api/comment.rs
+++ b/src/api/comment.rs
@@ -33,8 +33,8 @@ pub struct CommentOutput {
     blocked: bool,
 }
 
-pub async fn c2output<'r>(
-    p: &'r Post,
+pub async fn c2output(
+    p: &Post,
     cs: &[Comment],
     user: &CurrentUser,
     cached_block_dict: &HashMap<String, bool>,
diff --git a/src/api/post.rs b/src/api/post.rs
index 70d2c6d..aa3c502 100644
--- a/src/api/post.rs
+++ b/src/api/post.rs
@@ -87,7 +87,11 @@ async fn p2output(p: &Post, user: &CurrentUser, db: &Db, rconn: &RdsConn) -> Api
     Ok(PostOutput {
         pid: p.id,
         room_id: p.room_id,
-        text: can_view.then_some(p.content.clone()).unwrap_or_default(),
+        text: if can_view {
+            p.content.clone()
+        } else {
+            Default::default()
+        },
         cw: (!p.cw.is_empty()).then_some(p.cw.clone()),
         n_attentions: p.n_attentions,
         n_comments: p.n_comments,
diff --git a/src/cache.rs b/src/cache.rs
index 36d5982..ddc1e4b 100644
--- a/src/cache.rs
+++ b/src/cache.rs
@@ -180,7 +180,7 @@ impl PostListCache {
         let list_ref = post_list_cache()
             .try_get_with(self.key.clone(), async {
                 let mut items: Vec<(i64, i32)> =
-                    query_posts.await?.iter().map(|p| self.p2pair(&p)).collect();
+                    query_posts.await?.iter().map(|p| self.p2pair(p)).collect();
                 items.sort_by(|a, b| a.0.cmp(&b.0));
                 Ok(Arc::new(RwLock::new(items)))
             })
diff --git a/src/models.rs b/src/models.rs
index 05da0af..1830cbc 100644
--- a/src/models.rs
+++ b/src/models.rs
@@ -389,7 +389,7 @@ impl User {
     }
 
     pub async fn get_by_token(db: &Db, token: &str) -> Option<Self> {
-        let mut cacher = UserCache::init(token);
+        let cacher = UserCache::init(token);
         if let Some(u) = cacher.get().await {
             return Some(u);
         }
@@ -406,7 +406,7 @@ impl User {
             _ => token,
         };
         // dbg!(token);
-        let mut cacher = UserCache::init(token);
+        let cacher = UserCache::init(token);
         if let Some(u) = cacher.get().await {
             Some(u)
         } else {
diff --git a/src/rds_models.rs b/src/rds_models.rs
index 223ce69..3ff4bd2 100644
--- a/src/rds_models.rs
+++ b/src/rds_models.rs
@@ -176,7 +176,9 @@ impl Systemlog {
     pub async fn create(&self, rconn: &RdsConn) -> RedisResult<()> {
         let mut rconn = rconn.clone();
         if rconn.llen::<&str, isize>(KEY_SYSTEMLOG).await? > SYSTEMLOG_MAX_LEN {
-            rconn.ltrim(KEY_SYSTEMLOG, 0, SYSTEMLOG_MAX_LEN - 1).await?;
+            rconn
+                .ltrim::<_, ()>(KEY_SYSTEMLOG, 0, SYSTEMLOG_MAX_LEN - 1)
+                .await?;
         }
         rconn
             .lpush(KEY_SYSTEMLOG, serde_json::to_string(&self).unwrap())
@@ -258,9 +260,9 @@ pub struct CustomTitle;
 impl CustomTitle {
     async fn gen_and_set_secret(rconn: &RdsConn, title: &str) -> RedisResult<String> {
         let secret = random_string(8);
-        rconn
+        () = rconn
             .clone()
-            .set_ex(KEY_TITLE_SECRET!(&title), &secret, CUSTOM_TITLE_KEEP_TIME)
+            .set_ex::<_, _, ()>(KEY_TITLE_SECRET!(&title), &secret, CUSTOM_TITLE_KEEP_TIME)
             .await?;
         Ok(secret)
     }
@@ -283,8 +285,8 @@ impl CustomTitle {
             if let Some(t) = old_title {
                 clear_title_from_admins(&rconn, &t).await?;
             }
-            rconn.hset(KEY_CUSTOM_TITLE, namehash, title).await?;
-            rconn.hset(KEY_CUSTOM_TITLE, title, namehash).await?;
+            () = rconn.hset(KEY_CUSTOM_TITLE, namehash, title).await?;
+            () = rconn.hset(KEY_CUSTOM_TITLE, title, namehash).await?;
             Ok(Self::gen_and_set_secret(&rconn, title).await?)
         }
     }
@@ -297,7 +299,7 @@ impl CustomTitle {
         Ok(if let Some(title) = t {
             let s: Option<String> = rconn.clone().get(KEY_TITLE_SECRET!(title)).await?;
             let secret = if let Some(ss) = s {
-                rconn
+                () = rconn
                     .clone()
                     .expire(KEY_TITLE_SECRET!(title), CUSTOM_TITLE_KEEP_TIME as i64)
                     .await?;
@@ -345,7 +347,7 @@ impl PollOption {
     init!(i32, "hole_thu:poll_opts:{}");
 
     pub async fn set_list(&mut self, v: &Vec<String>) -> RedisResult<()> {
-        self.rconn.del(&self.key).await?;
+        () = self.rconn.del(&self.key).await?;
         self.rconn.rpush(&self.key, v).await
     }
 
@@ -409,9 +411,8 @@ pub async fn get_candidate_list(rconn: &RdsConn) -> RedisResult<Vec<String>> {
 
 pub async fn clear_title_from_admins(rconn: &RdsConn, title: &str) -> RedisResult<()> {
     let mut rconn = rconn.clone();
-    rconn.srem(KEY_CANDIDATE, title).await?;
-    rconn.srem(KEY_ADMIN, title).await?;
-    Ok(())
+    () = rconn.srem(KEY_CANDIDATE, title).await?;
+    rconn.srem(KEY_ADMIN, title).await
 }
 
 pub(crate) use clear_all;