all: use any instead of interface{}

My favorite part of generics.

Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>

util/clientmetric/clientmetric.go

@@ -256,7 +256,7 @@ func EncodeLogTailMetricsDelta() string {
 }
 
 var deltaPool = &sync.Pool{
-	New: func() interface{} {
+	New: func() any {
 		return new(deltaEncBuf)
 	},
 }

util/codegen/codegen.go

@@ -79,7 +79,7 @@ func NamedTypes(pkg *packages.Package) map[string]*types.Named {
 // for each package path that the caller must import for the returned code to compile.
 func AssertStructUnchanged(t *types.Struct, thisPkg *types.Package, tname, ctx string, imports map[string]struct{}) []byte {
 	buf := new(bytes.Buffer)
-	w := func(format string, args ...interface{}) {
+	w := func(format string, args ...any) {
 		fmt.Fprintf(buf, format+"\n", args...)
 	}
 	w("// A compilation failure here means this code must be regenerated, with the command at the top of this file.")

util/deephash/deephash.go

@@ -113,11 +113,11 @@ func (h *hasher) sum() (s Sum) {
 }
 
 var hasherPool = &sync.Pool{
-	New: func() interface{} { return new(hasher) },
+	New: func() any { return new(hasher) },
 }
 
 // Hash returns the hash of v.
-func Hash(v interface{}) (s Sum) {
+func Hash(v any) (s Sum) {
 	h := hasherPool.Get().(*hasher)
 	defer hasherPool.Put(h)
 	h.reset()
@@ -130,7 +130,7 @@ func Hash(v interface{}) (s Sum) {
 }
 
 // Update sets last to the hash of v and reports whether its value changed.
-func Update(last *Sum, v ...interface{}) (changed bool) {
+func Update(last *Sum, v ...any) (changed bool) {
 	sum := Hash(v)
 	if sum == *last {
 		// unchanged.
@@ -304,7 +304,7 @@ type mapHasher struct {
 }
 
 var mapHasherPool = &sync.Pool{
-	New: func() interface{} { return new(mapHasher) },
+	New: func() any { return new(mapHasher) },
 }
 
 type valueCache map[reflect.Type]reflect.Value

util/deephash/deephash_test.go

@@ -35,8 +35,8 @@ func (p appendBytes) AppendTo(b []byte) []byte {
 }
 
 func TestHash(t *testing.T) {
-	type tuple [2]interface{}
-	type iface struct{ X interface{} }
+	type tuple [2]any
+	type iface struct{ X any }
 	type scalars struct {
 		I8   int8
 		I16  int16
@@ -132,8 +132,8 @@ func TestDeepHash(t *testing.T) {
 	}
 }
 
-func getVal() []interface{} {
-	return []interface{}{
+func getVal() []any {
+	return []any{
 		&wgcfg.Config{
 			Name:      "foo",
 			Addresses: []netaddr.IPPrefix{netaddr.IPPrefixFrom(netaddr.IPFrom16([16]byte{3: 3}), 5)},
@@ -321,10 +321,10 @@ func TestExhaustive(t *testing.T) {
 // verify this doesn't loop forever, as it used to (Issue 2340)
 func TestMapCyclicFallback(t *testing.T) {
 	type T struct {
-		M map[string]interface{}
+		M map[string]any
 	}
 	v := &T{
-		M: map[string]interface{}{},
+		M: map[string]any{},
 	}
 	v.M["m"] = v.M
 	Hash(v)

util/jsonutil/unmarshal.go

@@ -20,13 +20,13 @@ type decoder struct {
 }
 
 var readerPool = sync.Pool{
-	New: func() interface{} {
+	New: func() any {
 		return bytes.NewReader(nil)
 	},
 }
 
 var decoderPool = sync.Pool{
-	New: func() interface{} {
+	New: func() any {
 		var d decoder
 		d.r = readerPool.Get().(*bytes.Reader)
 		d.dec = json.NewDecoder(d.r)
@@ -47,7 +47,7 @@ var decoderPool = sync.Pool{
 // don't use this Unmarshal.
 //
 // This Unmarshal allocates considerably less memory.
-func Unmarshal(b []byte, v interface{}) error {
+func Unmarshal(b []byte, v any) error {
 	d := decoderPool.Get().(*decoder)
 	d.r.Reset(b)
 	off := d.dec.InputOffset()

util/jsonutil/unmarshal_test.go

@@ -27,7 +27,7 @@ func TestCompareToStd(t *testing.T) {
 
 	for _, test := range tests {
 		b := []byte(test)
-		var ourV, stdV interface{}
+		var ourV, stdV any
 		ourErr := Unmarshal(b, &ourV)
 		stdErr := json.Unmarshal(b, &stdV)
 		if (ourErr == nil) != (stdErr == nil) {
@@ -47,7 +47,7 @@ func TestCompareToStd(t *testing.T) {
 }
 
 func BenchmarkUnmarshal(b *testing.B) {
-	var m interface{}
+	var m any
 	j := []byte("5")
 	b.ReportAllocs()
 	for i := 0; i < b.N; i++ {
@@ -56,7 +56,7 @@ func BenchmarkUnmarshal(b *testing.B) {
 }
 
 func BenchmarkStdUnmarshal(b *testing.B) {
-	var m interface{}
+	var m any
 	j := []byte("5")
 	b.ReportAllocs()
 	for i := 0; i < b.N; i++ {

util/multierr/multierr.go

@@ -78,7 +78,7 @@ func (e Error) Is(target error) bool {
 
 // As finds the first error in e that matches target, and if any is found,
 // sets target to that error value and returns true. Otherwise, it returns false.
-func (e Error) As(target interface{}) bool {
+func (e Error) As(target any) bool {
 	for _, err := range e.errs {
 		if ok := errors.As(err, target); ok {
 			return true

util/systemd/systemd_linux.go

@@ -25,7 +25,7 @@ type logOnce struct {
 	sync.Once
 }
 
-func (l *logOnce) logf(format string, args ...interface{}) {
+func (l *logOnce) logf(format string, args ...any) {
 	l.Once.Do(func() {
 		log.Printf(format, args...)
 	})
@@ -71,7 +71,7 @@ func Ready() {
 //    CPU: 2min 38.469s
 //    CGroup: /system.slice/tailscale.service
 //    └─26741 /nix/store/sv6cj4mw2jajm9xkbwj07k29dj30lh0n-tailscale-date.20200727/bin/tailscaled --port 41641
-func Status(format string, args ...interface{}) {
+func Status(format string, args ...any) {
 	err := notifier().Notify(sdnotify.Statusf(format, args...))
 	if err != nil {
 		statusOnce.logf("systemd: error notifying: %v", err)

util/systemd/systemd_nonlinux.go

@@ -7,5 +7,5 @@
 
 package systemd
 
-func Ready()                        {}
-func Status(string, ...interface{}) {}
+func Ready()                {}
+func Status(string, ...any) {}

util/uniq/slice.go

@@ -23,7 +23,7 @@ func (e badTypeError) Error() string {
 // It adjusts the length of the slice appropriately and zeros the tail.
 // eq reports whether (*sliceptr)[i] and (*sliceptr)[j] are equal.
 // ModifySlice does O(len(*sliceptr)) operations.
-func ModifySlice(sliceptr interface{}, eq func(i, j int) bool) {
+func ModifySlice(sliceptr any, eq func(i, j int) bool) {
 	rvp := reflect.ValueOf(sliceptr)
 	if rvp.Type().Kind() != reflect.Ptr {
 		panic(badTypeError{rvp.Type()})