// another n bytes. After Grow(n), at least n bytes can be written to the
// buffer without another allocation.
// If n is negative, Grow will panic.
// If the buffer can't grow it will panic with [ErrTooLarge].
func (b *Buffer) Grow(n int) {
	if n < 0 {
		panic("bytes.Buffer.Grow: negative count")
	}
	m := b.grow(n)
	b.buf = b.buf[:m]
}

// Write appends the contents of p to the buffer, growing the buffer as

// byte arrays sized based on width.
func NewBytePoolCap(maxSize uint64, width int, capwidth int) (bp *BytePoolCap) {
	if capwidth <= 0 {
		panic("total buffer capacity must be provided")
	}
	if capwidth < 64 {
		panic("buffer capped with smaller than 64 bytes is not supported")
	}
	if width > capwidth {
		panic("minimum buffer length cannot be > capacity of the buffer")
	}
	return &BytePoolCap{
		c:    make(chan []byte, maxSize),

const (
	policyCondEqual         = "eq"
	policyCondStartsWith    = "starts-with"
	policyCondContentLength = "content-length-range"
)

// toString - Safely convert interface to string without causing panic.
func toString(val interface{}) string {
	switch v := val.(type) {
	case string:
		return v
	default:
		return ""
	}
}

// toLowerString - safely convert interface to lower string

	}
	logJSON, err := json.Marshal(&log.Entry{
		Level:   FatalKind,
		Message: message,
		Time:    time.Now().UTC(),
		Trace:   &log.Trace{Message: message, Source: []string{getSource(6)}},
	})
	if err != nil {
		panic(err)
	}
	fmt.Fprintln(Output, string(logJSON))
	ExitFunc(1)
}

func (f fatalMsg) quiet(msg string, args ...interface{}) {
	f.pretty(msg, args...)
}

var (
	logTag      = "FATAL"

	desc, ok := m.descriptors[name]
	if !ok {
		panic(fmt.Sprintf("metric has no description: %s", name))
	}

	if len(labels)%2 != 0 {
		panic("labels must be a list of ordered key-value pairs")
	}

	validLabels := desc.getLabelSet()
	labelMap := make(map[string]string, len(labels)/2)
	for i := 0; i < len(labels); i += 2 {
		if _, ok := validLabels[labels[i]]; !ok {

// as we only guarantee a lookback buffer size of one, any subsequent calls to back()
// before calling next() may panic
func (s *scanner) back() {
	if s.ipos <= 0 {
		panic("back buffer exhausted")
	}
	s.ipos--
	s.pos--

The [GODEBUG History](#history) gives the exact defaults for each Go toolchain version.
For example, Go 1.21 introduces the `panicnil` setting,
controlling whether `panic(nil)` is allowed;
it defaults to `panicnil=0`, making `panic(nil)` a run-time error.
Using `panicnil=1` restores the behavior of Go 1.20 and earlier.

When compiling a work module or workspace that declares

		if debugPrint {
			fmt.Println("Mux", m.ID, "Handler took", time.Since(start).Round(time.Millisecond))
		}
		if r := recover(); r != nil {
			gridLogIf(ctx, fmt.Errorf("grid handler (%v) panic: %v", msg.Handler, r))
			err := RemoteErr(fmt.Sprintf("handler panic: %v", r))
			handlerErr = &err
		}
		if debugPrint {
			fmt.Println("muxServer: Mux", m.ID, "Returned with", handlerErr)
		}
	}()

	}
}

type panicReader struct{ panic bool }

func (r panicReader) Read(p []byte) (int, error) {
	if r.panic {
		panic("oops")
	}
	return 0, io.EOF
}

// Make sure that an empty Buffer remains empty when
// it is "grown" before a Read that panics
func TestReadFromPanicReader(t *testing.T) {

	// First verify non-panic behaviour
	var buf Buffer

At that point, the program is terminated and the error
condition is reported, including the value of the argument to <code>panic</code>.
This termination sequence is called <i>panicking</i>.
</p>

<pre>
panic(42)
panic("unreachable")
panic(Error("cannot parse"))
</pre>

<p>
The <code>recover</code> function allows a program to manage behavior
of a panicking goroutine.