all: use any instead of interface{}

My favorite part of generics.

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

types/dnstype/dnstype_clone.go

@@ -32,7 +32,7 @@ var _ResolverCloneNeedsRegeneration = Resolver(struct {
 // Clone duplicates src into dst and reports whether it succeeded.
 // To succeed, <src, dst> must be of types <*T, *T> or <*T, **T>,
 // where T is one of Resolver.
-func Clone(dst, src interface{}) bool {
+func Clone(dst, src any) bool {
 	switch src := src.(type) {
 	case *Resolver:
 		switch dst := dst.(type) {

types/logger/logger.go

@@ -28,7 +28,7 @@ import (
 // Logf is the basic Tailscale logger type: a printf-like func.
 // Like log.Printf, the format need not end in a newline.
 // Logf functions must be safe for concurrent use.
-type Logf func(format string, args ...interface{})
+type Logf func(format string, args ...any)
 
 // A Context is a context.Context that should contain a custom log function, obtainable from FromContext.
 // If no log function is present, FromContext will return log.Printf.
@@ -43,7 +43,7 @@ type jenc struct {
 	enc *json.Encoder
 }
 
-var jencPool = &sync.Pool{New: func() interface{} {
+var jencPool = &sync.Pool{New: func() any {
 	je := new(jenc)
 	je.enc = json.NewEncoder(&je.buf)
 	return je
@@ -61,7 +61,7 @@ var jencPool = &sync.Pool{New: func() interface{} {
 //
 // The level can be from 0 to 9. Levels from 1 to 9 are included in
 // the logged JSON object, like {"foo":123,"v":2}.
-func (logf Logf) JSON(level int, recType string, v interface{}) {
+func (logf Logf) JSON(level int, recType string, v any) {
 	je := jencPool.Get().(*jenc)
 	defer jencPool.Put(je)
 	je.buf.Reset()
@@ -96,7 +96,7 @@ func Ctx(ctx context.Context, fn Logf) Context {
 
 // WithPrefix wraps f, prefixing each format with the provided prefix.
 func WithPrefix(f Logf, prefix string) Logf {
-	return func(format string, args ...interface{}) {
+	return func(format string, args ...any) {
 		f(prefix+format, args...)
 	}
 }
@@ -119,7 +119,7 @@ func (w funcWriter) Write(p []byte) (int, error) {
 }
 
 // Discard is a Logf that throws away the logs given to it.
-func Discard(string, ...interface{}) {}
+func Discard(string, ...any) {}
 
 // limitData is used to keep track of each format string's associated
 // rate-limiting data.
@@ -165,7 +165,7 @@ func RateLimitedFnWithClock(logf Logf, f time.Duration, burst int, maxCache int,
 		msgCache = list.New()                  // a rudimentary LRU that limits the size of the map
 	)
 
-	return func(format string, args ...interface{}) {
+	return func(format string, args ...any) {
 		// Shortcut for formats with no rate limit
 		for _, sub := range rateFree {
 			if strings.Contains(format, sub) {
@@ -239,7 +239,7 @@ func LogOnChange(logf Logf, maxInterval time.Duration, timeNow func() time.Time)
 		tLastLogged = timeNow()
 	)
 
-	return func(format string, args ...interface{}) {
+	return func(format string, args ...any) {
 		s := fmt.Sprintf(format, args...)
 
 		mu.Lock()
@@ -270,13 +270,13 @@ func (fn ArgWriter) Format(f fmt.State, _ rune) {
 	argBufioPool.Put(bw)
 }
 
-var argBufioPool = &sync.Pool{New: func() interface{} { return bufio.NewWriterSize(ioutil.Discard, 1024) }}
+var argBufioPool = &sync.Pool{New: func() any { return bufio.NewWriterSize(ioutil.Discard, 1024) }}
 
 // Filtered returns a Logf that silently swallows some log lines.
 // Each inbound format and args is evaluated and printed to a string s.
 // The original format and args are passed to logf if and only if allow(s) returns true.
 func Filtered(logf Logf, allow func(s string) bool) Logf {
-	return func(format string, args ...interface{}) {
+	return func(format string, args ...any) {
 		msg := fmt.Sprintf(format, args...)
 		if !allow(msg) {
 			return
@@ -297,7 +297,7 @@ func LogfCloser(logf Logf) (newLogf Logf, close func()) {
 		defer mu.Unlock()
 		closed = true
 	}
-	newLogf = func(msg string, args ...interface{}) {
+	newLogf = func(msg string, args ...any) {
 		mu.Lock()
 		if closed {
 			mu.Unlock()

types/logger/logger_test.go

@@ -30,7 +30,7 @@ func TestStdLogger(t *testing.T) {
 }
 
 func logTester(want []string, t *testing.T, i *int) Logf {
-	return func(format string, args ...interface{}) {
+	return func(format string, args ...any) {
 		got := fmt.Sprintf(format, args...)
 		if *i >= len(want) {
 			t.Fatalf("Logging continued past end of expected input: %s", got)
@@ -204,7 +204,7 @@ func TestContext(t *testing.T) {
 
 	// Test that FromContext and Ctx work together.
 	var called bool
-	markCalled := func(string, ...interface{}) {
+	markCalled := func(string, ...any) {
 		called = true
 	}
 	ctx = Ctx(ctx, markCalled)
@@ -215,7 +215,7 @@ func TestContext(t *testing.T) {
 
 func TestJSON(t *testing.T) {
 	var buf bytes.Buffer
-	var logf Logf = func(f string, a ...interface{}) { fmt.Fprintf(&buf, f, a...) }
+	var logf Logf = func(f string, a ...any) { fmt.Fprintf(&buf, f, a...) }
 	logf.JSON(1, "foo", &tailcfg.Hostinfo{})
 	want := "[v\x00JSON]1" + `{"foo":{"OS":"","Hostname":""}}`
 	if got := buf.String(); got != want {

types/logger/rusage.go

@@ -13,7 +13,7 @@ import (
 // a prefixed log message to each line with the current binary memory usage
 // and max RSS.
 func RusagePrefixLog(logf Logf) Logf {
-	return func(f string, argv ...interface{}) {
+	return func(f string, argv ...any) {
 		var m runtime.MemStats
 		runtime.ReadMemStats(&m)
 		goMem := float64(m.HeapInuse+m.StackInuse) / (1 << 20)

types/opt/bool.go

@@ -30,7 +30,7 @@ func (b Bool) Get() (v bool, ok bool) {
 }
 
 // Scan implements database/sql.Scanner.
-func (b *Bool) Scan(src interface{}) error {
+func (b *Bool) Scan(src any) error {
 	if src == nil {
 		*b = ""
 		return nil

types/opt/bool_test.go

@@ -13,7 +13,7 @@ import (
 func TestBool(t *testing.T) {
 	tests := []struct {
 		name string
-		in   interface{}
+		in   any
 		want string // JSON
 	}{
 		{