Remove slices dependency. (#2930)

* Remove slices dependency.

* Fix nil pointer dereference bug.

---------

Co-authored-by: nobody <nobody@nowhere.mars>

common/reflect/marshal.go

@@ -3,7 +3,6 @@ package reflect
 import (
 	"encoding/json"
 	"reflect"
-	"slices"
 
 	cserial "github.com/xtls/xray-core/common/serial"
 )
@@ -18,6 +17,9 @@ func MarshalToJson(v interface{}) (string, bool) {
 }
 
 func marshalTypedMessage(v *cserial.TypedMessage, ignoreNullValue bool) interface{} {
+	if v == nil {
+		return nil
+	}
 	tmsg, err := v.GetInstance()
 	if err != nil {
 		return nil
@@ -111,8 +113,9 @@ func marshalKnownType(v interface{}, ignoreNullValue bool) (interface{}, bool) {
 	}
 }
 
-var valueKinds = []reflect.Kind{
-	reflect.Bool,
+func isValueKind(kind reflect.Kind) bool {
+	switch kind {
+	case reflect.Bool,
 		reflect.Int,
 		reflect.Int8,
 		reflect.Int16,
@@ -128,11 +131,11 @@ var valueKinds = []reflect.Kind{
 		reflect.Float64,
 		reflect.Complex64,
 		reflect.Complex128,
-	reflect.String,
+		reflect.String:
+		return true
+	default:
+		return false
 	}
-
-func isValueKind(kind reflect.Kind) bool {
-	return slices.Contains(valueKinds, kind)
 }
 
 func marshalInterface(v interface{}, ignoreNullValue bool) interface{} {

core/config.go

@@ -2,7 +2,6 @@ package core
 
 import (
 	"io"
-	"slices"
 	"strings"
 
 	"github.com/xtls/xray-core/common"
@@ -60,9 +59,12 @@ func GetMergedConfig(args cmdarg.Arg) (string, error) {
 	supported := []string{"json", "yaml", "toml"}
 	for _, file := range args {
 		format := getFormat(file)
-		if slices.Contains(supported, format) {
+		for _, s := range supported {
+			if s == format {
 				files = append(files, file)
 				formats = append(formats, format)
+				break
+			}
 		}
 	}
 	return ConfigMergedFormFiles(files, formats)