refactor: use more idiomatic api

Author: tottoto

src/common/access_control_allow_headers.rs

@@ -46,7 +46,7 @@ impl AccessControlAllowHeaders {
             .iter()
             .map(|s| s.parse().ok())
             .take_while(|val| val.is_some())
-            .filter_map(|val| val)
+            .flatten()
     }
 }
 

src/common/connection.rs

@@ -87,10 +87,7 @@ impl Connection {
     /// ```
     pub fn contains(&self, name: impl AsConnectionOption) -> bool {
         let s = name.as_connection_option();
-        self.0
-            .iter()
-            .find(|&opt| opt.eq_ignore_ascii_case(s))
-            .is_some()
+        self.0.iter().any(|opt| opt.eq_ignore_ascii_case(s))
     }
 }
 

src/common/content_encoding.rs

@@ -72,7 +72,7 @@ impl ContentEncoding {
     /// ```
     pub fn contains(&self, coding: impl AsCoding) -> bool {
         let s = coding.as_coding();
-        self.0.iter().find(|&opt| opt == s).is_some()
+        self.0.iter().any(|opt| opt == s)
     }
 }
 

src/common/strict_transport_security.rs

@@ -111,13 +111,13 @@ fn from_str(s: &str) -> Result<StrictTransportSecurity, ::Error> {
                 }
             }
         })
-        .fold(Some((None, None)), |res, dir| match (res, dir) {
-            (Some((None, sub)), Some(Directive::MaxAge(age))) => Some((Some(age), sub)),
-            (Some((age, None)), Some(Directive::IncludeSubdomains)) => Some((age, Some(()))),
-            (Some((Some(_), _)), Some(Directive::MaxAge(_)))
-            | (Some((_, Some(_))), Some(Directive::IncludeSubdomains))
+        .try_fold((None, None), |res, dir| match (res, dir) {
+            ((None, sub), Some(Directive::MaxAge(age))) => Some((Some(age), sub)),
+            ((age, None), Some(Directive::IncludeSubdomains)) => Some((age, Some(()))),
+            ((Some(_), _), Some(Directive::MaxAge(_)))
+            | ((_, Some(_)), Some(Directive::IncludeSubdomains))
             | (_, None) => None,
-            (res, _) => res,
+            (res, _) => Some(res),
         })
         .and_then(|res| match res {
             (Some(age), sub) => Some(StrictTransportSecurity {

src/util/flat_csv.rs

@@ -114,7 +114,7 @@ impl<'a, Sep: Separator> FromIterator<&'a HeaderValue> for FlatCsv<Sep> {
             .next()
             .cloned()
             .map(|val| BytesMut::from(val.as_bytes()))
-            .unwrap_or_else(|| BytesMut::new());
+            .unwrap_or_default();
 
         for val in values {
             buf.extend_from_slice(&[Sep::BYTE, b' ']);
@@ -145,7 +145,7 @@ impl<Sep: Separator> FromIterator<HeaderValue> for FlatCsv<Sep> {
         let mut buf = values
             .next()
             .map(|val| BytesMut::from(val.as_bytes()))
-            .unwrap_or_else(|| BytesMut::new());
+            .unwrap_or_default();
 
         for val in values {
             buf.extend_from_slice(&[Sep::BYTE, b' ']);