// sparse files, and other features.
	//
	// It is recommended that PAX be chosen over GNU unless the target
	// application can only parse GNU formatted archives.
	//
	// Reference:
	//	https://www.gnu.org/software/tar/manual/html_node/Standard.html
	FormatGNU

	// Schily's tar format, which is incompatible with USTAR.
	// This does not cover STAR extensions to the PAX format; these fall under
	// the PAX format.
	formatSTAR

// scanning lines, a [SplitFunc] can return (0, nil, nil) to signal the
// [Scanner] to read more data into the slice and try again with a
// longer slice starting at the same point in the input.
//
// The function is never called with an empty data slice unless atEOF
// is true. If atEOF is true, however, data may be non-empty and,
// as always, holds unprocessed text.
type SplitFunc func(data []byte, atEOF bool) (advance int, token []byte, err error)

			if p != j {
				t.Errorf("IndexByte(%q, %d) = %d", b[i:i+15], 100+j, p)
			}
		}
		for j := 0; j < 15; j++ {
			b[i+j] = 0
		}
	}
	// Make sure matches outside the slice never trigger.
	for i := 0; i <= len(b)-15; i++ {
		for j := 0; j < 15; j++ {
			b[i+j] = 1
		}
		for j := 0; j < 15; j++ {
			p := IndexByte(b[i:i+15], byte(0))
			if p != -1 {

	if _, err = rs.Seek(r.baseOffset+int64(end.directoryOffset), io.SeekStart); err != nil {
		return err
	}
	buf := bufio.NewReader(rs)

	// The count of files inside a zip is truncated to fit in a uint16.
	// Gloss over this by reading headers until we encounter
	// a bad one, and then only report an ErrFormat or UnexpectedEOF if
	// the file count modulo 65536 is incorrect.
	for {
		f := &File{zip: r, zipr: rdr}

	Flags          uint16

	// Method is the compression method. If zero, Store is used.
	Method uint16

	// Modified is the modified time of the file.
	//
	// When reading, an extended timestamp is preferred over the legacy MS-DOS
	// date field, and the offset between the times is used as the timezone.
	// If only the MS-DOS date is present, the timezone is assumed to be UTC.
	//

func clear[T ~[]Type | ~map[Type]Type1](t T)

// The close built-in function closes a channel, which must be either
// bidirectional or send-only. It should be executed only by the sender,
// never the receiver, and has the effect of shutting down the channel after
// the last sent value is received. After the last value has been received
// from a closed channel c, any receive from c will succeed without

	var f formatter
	blk := tw.templateV7Plus(hdr, f.formatString, f.formatOctal)
	f.formatString(blk.toUSTAR().prefix(), namePrefix)
	blk.setFormat(FormatUSTAR)
	if f.err != nil {
		return f.err // Should never happen since header is validated
	}
	return tw.writeRawHeader(blk, hdr.Size, hdr.Typeflag)
}

func (tw *Writer) writePAXHeader(hdr *Header, paxHdrs map[string]string) error {
	realName, realSize := hdr.Name, hdr.Size

	// should therefore be always resident in the L1 cache - until we
	// have completed the construction of the result.
	// This yields significant speedups (up to +100%) in cases where
	// the result length is large (roughly, over L2 cache size).
	const chunkLimit = 8 * 1024
	chunkMax := n
	if chunkMax > chunkLimit {
		chunkMax = chunkLimit / len(b) * len(b)
		if chunkMax == 0 {
			chunkMax = len(b)
		}
	}

// it is no longer referenced, so it must be kept alive (see runtime.KeepAlive)
// until any memory allocated from it is no longer needed.
//
// An Arena must never be used concurrently by multiple goroutines.
type Arena struct {
	a unsafe.Pointer
}

// NewArena allocates a new arena.
func NewArena() *Arena {
	return &Arena{a: runtime_arena_newArena()}
}

	func C.GoBytes(unsafe.Pointer, C.int) []byte

As a special case, C.malloc does not call the C library malloc directly
but instead calls a Go helper function that wraps the C library malloc
but guarantees never to return nil. If C's malloc indicates out of memory,
the helper function crashes the program, like when Go itself runs out
of memory. Because C.malloc cannot fail, it has no two-result form
that returns errno.