go tool fix -r cftype <pkg>
	go tool fix -r jni <pkg>

It will replace nil with 0 in the appropriate places.

The EGLDisplay case was introduced in Go 1.12. Use the egl rewrite
to auto-update code from Go 1.11 and earlier:

	go tool fix -r egl <pkg>

The EGLConfig case was introduced in Go 1.15. Use the eglconf rewrite
to auto-update code from Go 1.14 and earlier:

	go tool fix -r eglconf <pkg>

	switch m := fs.FileMode(fi.h.Mode) &^ 07777; m {
	case c_ISDIR:
		mode |= fs.ModeDir
	case c_ISFIFO:
		mode |= fs.ModeNamedPipe
	case c_ISLNK:
		mode |= fs.ModeSymlink
	case c_ISBLK:
		mode |= fs.ModeDevice
	case c_ISCHR:
		mode |= fs.ModeDevice
		mode |= fs.ModeCharDevice
	case c_ISSOCK:
		mode |= fs.ModeSocket
	}

	switch fi.h.Typeflag {
	case TypeSymlink:
		mode |= fs.ModeSymlink

	}()
	buf2.ReadFrom(panicReader{panic: true})
}

func TestReadFromNegativeReader(t *testing.T) {
	var b Buffer
	defer func() {
		switch err := recover().(type) {
		case nil:
			t.Fatal("bytes.Buffer.ReadFrom didn't panic")
		case error:
			// this is the error string of errNegativeRead
			wantError := "bytes.Buffer: reader returned negative count from Read"
			if err.Error() != wantError {

//	slice = append(slice, anotherSlice...)
//
// As a special case, it is legal to append a string to a byte slice, like this:
//
//	slice = append([]byte("hello "), "world"...)
func append(slice []Type, elems ...Type) []Type

// The copy built-in function copies elements from a source slice into a
// destination slice. (As a special case, it also will copy bytes from a

	// Output:
	// 8
	// 9
	// -1
}

func ExampleMap() {
	rot13 := func(r rune) rune {
		switch {
		case r >= 'A' && r <= 'Z':
			return 'A' + (r-'A'+13)%26
		case r >= 'a' && r <= 'z':
			return 'a' + (r-'a'+13)%26
		}
		return r
	}
	fmt.Printf("%s\n", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
	// Output:

			s = "ideal-char"
		case types.UntypedFloat:
			s = "ideal-float"
		case types.UntypedComplex:
			s = "ideal-complex"
		case types.UntypedString:
			s = "ideal-string"
		case types.UntypedNil:
			panic("should never see untyped nil type")
		default:
			switch s {
			case "byte":
				s = "uint8"
			case "rune":
				s = "int32"
			}
		}
		buf.WriteString(s)

	case *types.Array:

		}
		var id64 int64
		switch k {
		case paxPath:
			hdr.Name = v
		case paxLinkpath:
			hdr.Linkname = v
		case paxUname:
			hdr.Uname = v
		case paxGname:
			hdr.Gname = v
		case paxUid:
			id64, err = strconv.ParseInt(v, 10, 64)
			hdr.Uid = int(id64) // Integer overflow possible
		case paxGid:
			id64, err = strconv.ParseInt(v, 10, 64)

			return ok1 && ok2
		}
		return x == y
	}
	for _, v := range vectors {
		t.Run(path.Base(v.file), func(t *testing.T) {
			const maxSize = 10 << 10 // 10KiB
			buf := new(bytes.Buffer)
			tw := NewWriter(iotest.TruncateWriter(buf, maxSize))

			for i, tf := range v.tests {
				switch tf := tf.(type) {
				case testHeader:
					err := tw.WriteHeader(&tf.hdr)
					if !equalError(err, tf.wantErr) {

	// valid UTF-8 string, then we set the UTF-8 bit.
	//
	// For the case, where the user explicitly wants to specify the encoding
	// as UTF-8, they will need to set the flag bit themselves.
	utf8Valid1, utf8Require1 := detectUTF8(fh.Name)
	utf8Valid2, utf8Require2 := detectUTF8(fh.Comment)
	switch {
	case fh.NonUTF8:
		fh.Flags &^= 0x800
	case (utf8Require1 || utf8Require2) && (utf8Valid1 && utf8Valid2):
		fh.Flags |= 0x800

The defaults that will be compiled into a main package
are reported by the command:

{{raw `
	go list -f '{{.DefaultGODEBUG}}' my/main/package
`}}

Only differences from the base Go toolchain defaults are reported.

When testing a package, `//go:debug` lines in the `*_test.go`
files are treated as directives for the test's main package.