style: simplify statements for readability

examples/add_anchor.rs

@@ -20,6 +20,6 @@ fn main() {
         pf.try_add_anchor(&anchor_name, pfctl::AnchorKind::Scrub)
             .expect("Unable to add scrub anchor");
 
-        println!("Added {} as every anchor type", anchor_name);
+        println!("Added {anchor_name} as every anchor type");
     }
 }

examples/add_rules.rs

@@ -114,7 +114,7 @@ fn main() {
     pf.add_scrub_rule(ANCHOR_NAME, &scrub_rule)
         .expect("Unable to add scrub rule");
 
-    println!("Added a bunch of rules to the {} anchor.", ANCHOR_NAME);
+    println!("Added a bunch of rules to the {ANCHOR_NAME} anchor.");
     println!("Run this command to remove them:");
-    println!("sudo pfctl -a {} -F all", ANCHOR_NAME);
+    println!("sudo pfctl -a {ANCHOR_NAME} -F all");
 }

examples/flush_rules.rs

@@ -15,18 +15,18 @@ fn main() {
     for anchor_name in env::args().skip(1) {
         pf.flush_rules(&anchor_name, pfctl::RulesetKind::Filter)
             .expect("Unable to flush filter rules");
-        println!("Flushed filter rules under anchor {}", anchor_name);
+        println!("Flushed filter rules under anchor {anchor_name}");
 
         pf.flush_rules(&anchor_name, pfctl::RulesetKind::Nat)
             .expect("Unable to flush nat rules");
-        println!("Flushed nat rules under anchor {}", anchor_name);
+        println!("Flushed nat rules under anchor {anchor_name}");
 
         pf.flush_rules(&anchor_name, pfctl::RulesetKind::Redirect)
             .expect("Unable to flush redirect rules");
-        println!("Flushed redirect rules under anchor {}", anchor_name);
+        println!("Flushed redirect rules under anchor {anchor_name}");
 
         pf.flush_rules(&anchor_name, pfctl::RulesetKind::Scrub)
             .expect("Unable to flush scrub rules");
-        println!("Flushed scrub rules under anchor {}", anchor_name);
+        println!("Flushed scrub rules under anchor {anchor_name}");
     }
 }

examples/transaction.rs

@@ -54,7 +54,7 @@ fn main() {
     pf.set_rules(ANCHOR_NAME, trans_change)
         .expect("Unable to set rules");
 
-    println!("Added a bunch of rules to the {} anchor.", ANCHOR_NAME);
+    println!("Added a bunch of rules to the {ANCHOR_NAME} anchor.");
     println!("Run this command to remove them:");
-    println!("sudo pfctl -a {} -F all", ANCHOR_NAME);
+    println!("sudo pfctl -a {ANCHOR_NAME} -F all");
 }

src/rule/mod.rs

@@ -119,10 +119,8 @@ impl FilterRule {
             | (StatePolicy::Modulate, Proto::Tcp)
             | (StatePolicy::SynProxy, Proto::Tcp) => Ok(self.keep_state),
             (state_policy, proto) => {
-                let msg = format!(
-                    "StatePolicy {:?} and protocol {:?} are incompatible",
-                    state_policy, proto
-                );
+                let msg =
+                    format!("StatePolicy {state_policy:?} and protocol {proto:?} are incompatible");
                 Err(Error::from(ErrorInternal::InvalidRuleCombination(msg)))
             }
         }
@@ -360,7 +358,7 @@ fn compatible_af(af1: AddrFamily, af2: AddrFamily) -> Result<AddrFamily> {
         (af, AddrFamily::Any) => Ok(af),
         (AddrFamily::Any, af) => Ok(af),
         (af1, af2) => {
-            let msg = format!("AddrFamily {} and {} are incompatible", af1, af2);
+            let msg = format!("AddrFamily {af1} and {af2} are incompatible");
             Err(Error::from(ErrorInternal::InvalidRuleCombination(msg)))
         }
     }