rlp: use reflect.TypeFor (#32317)

Co-authored-by: Felix Lange <[email protected]>

Author: cuiweixie

rlp/decode.go

@@ -148,9 +148,9 @@ func addErrorContext(err error, ctx string) error {
 }
 
 var (
-	decoderInterface = reflect.TypeOf(new(Decoder)).Elem()
-	bigInt           = reflect.TypeOf(big.Int{})
-	u256Int          = reflect.TypeOf(uint256.Int{})
+	decoderInterface = reflect.TypeFor[Decoder]()
+	bigInt           = reflect.TypeFor[big.Int]()
+	u256Int          = reflect.TypeFor[uint256.Int]()
 )
 
 func makeDecoder(typ reflect.Type, tags rlpstruct.Tags) (dec decoder, err error) {
@@ -512,7 +512,7 @@ func makeNilPtrDecoder(etype reflect.Type, etypeinfo *typeinfo, ts rlpstruct.Tag
 	}
 }
 
-var ifsliceType = reflect.TypeOf([]interface{}{})
+var ifsliceType = reflect.TypeFor[[]any]()
 
 func decodeInterface(s *Stream, val reflect.Value) error {
 	if val.Type().NumMethod() != 0 {

rlp/encode.go

@@ -133,7 +133,7 @@ func puthead(buf []byte, smalltag, largetag byte, size uint64) int {
 	return sizesize + 1
 }
 
-var encoderInterface = reflect.TypeOf(new(Encoder)).Elem()
+var encoderInterface = reflect.TypeFor[Encoder]()
 
 // makeWriter creates a writer function for the given type.
 func makeWriter(typ reflect.Type, ts rlpstruct.Tags) (writer, error) {

rlp/raw.go

@@ -26,7 +26,7 @@ import (
 // not verify whether the content of RawValues is valid RLP.
 type RawValue []byte
 
-var rawValueType = reflect.TypeOf(RawValue{})
+var rawValueType = reflect.TypeFor[RawValue]()
 
 // StringSize returns the encoded size of a string.
 func StringSize(s string) uint64 {