func IndexFunc(s []byte, f func(r rune) bool) int {
	return indexFunc(s, f, true)
}

// LastIndexFunc interprets s as a sequence of UTF-8-encoded code points.
// It returns the byte index in s of the last Unicode
// code point satisfying f(c), or -1 if none do.
func LastIndexFunc(s []byte, f func(r rune) bool) int {
	return lastIndexFunc(s, f, true)
}

// indexFunc is the same as IndexFunc except that if

	// Output:
	// 3
	// 8
	// -1
}

func ExampleLastIndexFunc() {
	fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsLetter))
	fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsPunct))
	fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsNumber))
	// Output:
	// 8
	// 9
	// -1
}

func ExampleMap() {

		first := IndexFunc([]byte(tc.in), tc.f.f)
		if first != tc.first {
			t.Errorf("IndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, first, tc.first)
		}
		last := LastIndexFunc([]byte(tc.in), tc.f.f)
		if last != tc.last {
			t.Errorf("LastIndexFunc(%q, %s) = %d; want %d", tc.in, tc.f.name, last, tc.last)
		}
	}
}

type ReplaceTest struct {
	in       string
	old, new string
	n        int

pkg bytes, func IndexRune([]uint8, int32) int
pkg bytes, func Join([][]uint8, []uint8) []uint8
pkg bytes, func LastIndex([]uint8, []uint8) int
pkg bytes, func LastIndexAny([]uint8, string) int
pkg bytes, func LastIndexFunc([]uint8, func(int32) bool) int
pkg bytes, func Map(func(int32) int32, []uint8) []uint8
pkg bytes, func NewBuffer([]uint8) *Buffer
pkg bytes, func NewBufferString(string) *Buffer
pkg bytes, func NewReader([]uint8) *Reader