3. What did you do?
4. What did you expect to see?
5. What did you see instead?

For change proposals, see [Proposing Changes To Go](https://go.dev/s/proposal-process).

## Contributing code

Please read the [Contribution Guidelines](https://golang.org/doc/contribute.html) before sending patches.

Unless otherwise noted, the Go source files are distributed under

pkg syscall, type Conn interface { SyscallConn }
pkg syscall, type Conn interface, SyscallConn() (RawConn, error)
pkg syscall, type RawConn interface { Control, Read, Write }
pkg syscall, type RawConn interface, Control(func(uintptr)) error
pkg syscall, type RawConn interface, Read(func(uintptr) bool) error
pkg syscall, type RawConn interface, Write(func(uintptr) bool) error
pkg testing, method (*B) Helper()
pkg testing, method (*T) Helper()

		b := w.AvailableBuffer()
		b = strconv.AppendInt(b, i, 10)
		b = append(b, ' ')
		w.Write(b)
	}
	w.Flush()
	// Output: 1 2 3 4
}

// The simplest use of a Scanner, to read standard input as a set of lines.
func ExampleScanner_lines() {
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		fmt.Println(scanner.Text()) // Println will add back the final '\n'
	}

	fmt.Printf("%s\n", b.Next(2))
	fmt.Printf("%s\n", b.Next(2))
	fmt.Printf("%s", b.Next(2))
	// Output:
	// ab
	// cd
	// e
}

func ExampleBuffer_Read() {
	var b bytes.Buffer
	b.Grow(64)
	b.Write([]byte("abcde"))
	rdbuf := make([]byte, 1)
	n, err := b.Read(rdbuf)
	if err != nil {
		panic(err)
	}
	fmt.Println(n)
	fmt.Println(b.String())
	fmt.Println(string(rdbuf))
	// Output:
	// 1
	// bcde

pkg net/http, var ErrAbortHandler error
pkg net/http, var ErrServerClosed error
pkg net/http, var NoBody noBody
pkg net/mail, func ParseDate(string) (time.Time, error)
pkg net, method (*Buffers) Read([]uint8) (int, error)
pkg net, method (*Buffers) WriteTo(io.Writer) (int64, error)
pkg net, method (*Resolver) LookupAddr(context.Context, string) ([]string, error)

denial of service attacks, this setting and default was backported to Go
1.19.13, Go 1.20.8, and Go 1.21.1.

Go 1.22 made it an error for a request or response read by a net/http
client or server to have an empty Content-Length header.
This behavior is controlled by the `httplaxcontentlength` setting.

Go 1.22 changed the behavior of ServeMux to accept extended

}

func TestToValidUTF8(t *testing.T) {
	for _, tc := range toValidUTF8Tests {
		got := ToValidUTF8([]byte(tc.in), []byte(tc.repl))
		if !Equal(got, []byte(tc.out)) {
			t.Errorf("ToValidUTF8(%q, %q) = %q; want %q", tc.in, tc.repl, got, tc.out)
		}
	}
}

func TestTrimSpace(t *testing.T) { runStringTests(t, TrimSpace, "TrimSpace", trimSpaceTests) }

type RepeatTest struct {

pkg syscall (freebsd-riscv64), const EVFILT_PROC = -5 #53466
pkg syscall (freebsd-riscv64), const EVFILT_PROC ideal-int #53466
pkg syscall (freebsd-riscv64), const EVFILT_READ = -1 #53466
pkg syscall (freebsd-riscv64), const EVFILT_READ ideal-int #53466
pkg syscall (freebsd-riscv64), const EVFILT_SIGNAL = -6 #53466
pkg syscall (freebsd-riscv64), const EVFILT_SIGNAL ideal-int #53466

do exactly this.
</p>

<p>
A read of an array, struct, or complex number
may by implemented as a read of each individual sub-value
(array element, struct field, or real/imaginary component),
in any order.
Similarly, a write of an array, struct, or complex number
may be implemented as a write of each individual sub-value,
in any order.
</p>

<p>
A read <i>r</i> of a memory location <i>x</i>
holding a value

		t.Errorf("r.Len(): got %d, want %d", got, want)
	}
	if n, err := r.Read(make([]byte, 10)); err != nil || n != 10 {
		t.Errorf("Read failed: read %d %v", n, err)
	}
	if got, want := r.Len(), 1; got != want {
		t.Errorf("r.Len(): got %d, want %d", got, want)
	}
	if n, err := r.Read(make([]byte, 1)); err != nil || n != 1 {
		t.Errorf("Read failed: read %d %v; want 1, nil", n, err)
	}
	if got, want := r.Len(), 0; got != want {