}
}

// Buffer sets the initial buffer to use when scanning
// and the maximum size of buffer that may be allocated during scanning.
// The maximum token size must be less than the larger of max and cap(buf).
// If max <= cap(buf), [Scanner.Scan] will use this buffer only and do no allocation.
//
// By default, [Scanner.Scan] uses an internal buffer and sets the
// maximum token size to [MaxScanTokenSize].
//

		b = append(b, ' ')
		buf.Write(b)
	}
	os.Stdout.Write(buf.Bytes())
	// Output: 0 1 2 3
}

func ExampleBuffer_Cap() {
	buf1 := bytes.NewBuffer(make([]byte, 10))
	buf2 := bytes.NewBuffer(make([]byte, 0, 10))
	fmt.Println(buf1.Cap())
	fmt.Println(buf2.Cap())
	// Output:
	// 10
	// 10
}

func ExampleBuffer_Grow() {
	var b bytes.Buffer
	b.Grow(64)
	bb := b.Bytes()

// capacity" section for details.
func len(v Type) int

// The cap built-in function returns the capacity of v, according to its type:
//
//	Array: the number of elements in v (same as len(v)).
//	Pointer to array: the number of elements in *v (same as len(v)).
//	Slice: the maximum length the slice can reach when resliced;
//	if v is nil, cap(v) is zero.
//	Channel: the channel buffer capacity, in units of elements;

// not be used after the arena is freed. Accessing the underlying storage of the
// slice after free may result in a fault, but this fault is also not guaranteed.
func MakeSlice[T any](a *Arena, len, cap int) []T {
	var sl []T
	runtime_arena_arena_Slice(a.a, &sl, cap)
	return sl[:len]
}

// Clone makes a shallow copy of the input value that is no longer bound to any
// arena it may have been allocated from, returning the copy. If it was not

	defer a.Free()

	tt := arena.New[T1](a)
	tt.n = 1

	ts := arena.MakeSlice[T1](a, 99, 100)
	if len(ts) != 99 {
		t.Errorf("Slice() len = %d, want 99", len(ts))
	}
	if cap(ts) != 100 {
		t.Errorf("Slice() cap = %d, want 100", cap(ts))
	}
	ts[1].n = 42
}

func TestSmokeLarge(t *testing.T) {
	a := arena.NewArena()
	defer a.Free()
	for i := 0; i < 10*64; i++ {
		_ = arena.New[T2](a)
	}

			if !reflect.DeepEqual(a, b) {
				t.Errorf("Split disagrees withSplitN(%q, %q, %d) = %v; want %v", tt.s, tt.sep, tt.n, b, a)
			}
		}
		if len(a) > 0 {
			in, out := a[0], s
			if cap(in) == cap(out) && &in[:1][0] == &out[:1][0] {
				t.Errorf("Join(%#v, %q) didn't copy", a, tt.sep)
			}
		}
	}
}

var splitaftertests = []SplitTest{
	{abcd, "a", -1, []string{"a", "bcd"}},

	var cap0 int
	for i := 0; i < 5<<10; i++ {
		b.Write(buf)
		b.Read(buf)
		if i == 0 {
			cap0 = b.Cap()
		}
	}
	cap1 := b.Cap()
	// (*Buffer).grow allows for 2x capacity slop before sliding,
	// so set our error threshold at 3x.
	if cap1 > cap0*3 {
		t.Errorf("buffer cap = %d; too big (grew from %d)", cap1, cap0)
	}
}

func BenchmarkWriteByte(b *testing.B) {
	const n = 4 << 10

func (b *Buffer) Len() int { return len(b.buf) - b.off }

// Cap returns the capacity of the buffer's underlying byte slice, that is, the
// total space allocated for the buffer's data.
func (b *Buffer) Cap() int { return cap(b.buf) }

// Available returns how many bytes are unused in the buffer.
func (b *Buffer) Available() int { return cap(b.buf) - len(b.buf) }

	nesting := 0
	colon := -1
	for tok != '\n' && tok != ';' {
		// Process one operand.
		var items []lex.Token
		if cap(operands) > len(operands) {
			// Reuse scratch items slice.
			items = operands[:cap(operands)][len(operands)][:0]
		} else {
			items = make([]lex.Token, 0, 3)
		}
		for {
			tok = p.nextToken()
			if len(operands) == 0 && len(items) == 0 {

		// Obtain a buffer to append to.
		b := w.AvailableBuffer()
		if w.Available() != cap(b) {
			t.Fatalf("Available() = %v, want %v", w.Available(), cap(b))
		}

		// While not recommended, it is valid to append to a shifted buffer.
		// This forces Write to copy the input.
		if rn.Intn(8) == 0 && cap(b) > 0 {
			b = b[1:1:cap(b)]
		}

		// Append a random integer of varying width.