for all of ./...

routing/gateway.go

@@ -3,6 +3,7 @@ package routing
 import (
 	"fmt"
 	"net/netip"
+	"strings"
 )
 
 const (
@@ -13,14 +14,14 @@ const (
 type Gateways []Gateway
 
 func (g Gateways) String() string {
-	str := ""
+	var str strings.Builder
 	for i, gw := range g {
-		str += gw.String()
+		str.WriteString(gw.String())
 		if i < len(g)-1 {
-			str += ", "
+			str.WriteString(", ")
 		}
 	}
-	return str
+	return str.String()
 }
 
 type Gateway struct {