for _, growLen := range []int{0, 100, 1000, 10000, 100000} {
		for _, startLen := range []int{0, 100, 1000, 10000, 100000} {
			xBytes := Repeat(x, startLen)

			buf := NewBuffer(xBytes)
			// If we read, this affects buf.off, which is good to test.
			readBytes, _ := buf.Read(tmp)
			yBytes := Repeat(y, growLen)
			allocs := testing.AllocsPerRun(100, func() {
				buf.Grow(growLen)
				buf.Write(yBytes)
			})

	var z *Reader
	var err error
	var raw []byte
	if zt.Source != nil {
		rat, size := zt.Source()
		z, err = NewReader(rat, size)
		raw = make([]byte, size)
		if _, err := rat.ReadAt(raw, 0); err != nil {
			t.Errorf("ReadAt error=%v", err)
			return
		}
	} else {
		path := filepath.Join("testdata", zt.Name)
		if zt.Obscured {
			tf, err := obscuretestdata.DecodeToTempFile(path)
			if err != nil {

entirely using GODEBUG=cgocheck=0. Complete checking of pointer
handling, at some cost in run time, is available by setting
GOEXPERIMENT=cgocheck2 at build time.

It is possible to defeat this enforcement by using the unsafe package,
and of course there is nothing stopping the C code from doing anything
it likes. However, programs that break these rules are likely to fail
in unexpected and unpredictable ways.

x = v              // x has value (*T)(nil) and dynamic type *T
</pre>

<p>
A variable's value is retrieved by referring to the variable in an
<a href="#Expressions">expression</a>; it is the most recent value
<a href="#Assignments">assigned</a> to the variable.
If a variable has not yet been assigned a value, its value is the
<a href="#The_zero_value">zero value</a> for its type.
</p>

		return part.off+part.n > off
	})
	parts := r.buf[skipParts:]
	if len(parts) > 0 {
		skipBytes := off - parts[0].off
		for _, part := range parts {
			repeat := int(min(part.n-skipBytes, int64(len(p)-n)))
			memset(p[n:n+repeat], part.b)
			n += repeat
			if n == len(p) {
				return
			}
			skipBytes = 0
		}
	}
	if n != len(p) {
		err = io.ErrUnexpectedEOF
	}
	return
}

The [Repeat] function returns a new slice that repeats the

func TestRepeat(t *testing.T) {
	for _, tt := range RepeatTests {
		tin := []byte(tt.in)
		tout := []byte(tt.out)
		a := Repeat(tin, tt.count)
		if !Equal(a, tout) {
			t.Errorf("Repeat(%q, %d) = %q; want %q", tin, tt.count, a, tout)
			continue
		}
	}
}

func repeat(b []byte, count int) (err error) {
	defer func() {
		if r := recover(); r != nil {
			switch v := r.(type) {
			case error:

	fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
	fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
	// Output:
	// 3
	// 16
}

func ExampleRepeat() {
	fmt.Printf("ba%s", bytes.Repeat([]byte("na"), 2))
	// Output: banana
}

func ExampleReplace() {
	fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("k"), []byte("ky"), 2))

		}
		i += wid
	}
	return b
}

// Repeat returns a new byte slice consisting of count copies of b.
//
// It panics if count is negative or if the result of (len(b) * count)
// overflows.
func Repeat(b []byte, count int) []byte {
	if count == 0 {
		return []byte{}
	}

	// Since we cannot return an error on overflow,
	// we should panic if the repeat will generate an overflow.
	// See golang.org/issue/16237.

now unbuffered, with capacity 0.
The main effect of this change is that Go now guarantees
that for any call to a `Reset` or `Stop` method, no stale values
prepared before that call will be sent or received after the call.
Earlier versions of Go used channels with a one-element buffer,
making it difficult to use `Reset` and `Stop` correctly.
A visible effect of this change is that `len` and `cap` of timer channels