// 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

	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) }

	}
}

// 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].
//

// 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;

		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()

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
now returns 0 instead of 1, which may affect programs that
poll the length to decide whether a receive on the timer channel
will succeed.
Such code should use a non-blocking receive instead.

pkg syscall (freebsd-arm), const SYS_CAP_FCNTLS_GET = 537
pkg syscall (freebsd-arm), const SYS_CAP_FCNTLS_GET ideal-int
pkg syscall (freebsd-arm), const SYS_CAP_FCNTLS_LIMIT = 536
pkg syscall (freebsd-arm), const SYS_CAP_FCNTLS_LIMIT ideal-int
pkg syscall (freebsd-arm), const SYS_CAP_IOCTLS_GET = 535
pkg syscall (freebsd-arm), const SYS_CAP_IOCTLS_GET ideal-int
pkg syscall (freebsd-arm), const SYS_CAP_IOCTLS_LIMIT = 534

		// 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.

</p>

<pre>
s := make([]int, 10, 100)       // slice with len(s) == 10, cap(s) == 100
s := make([]int, 1e3)           // slice with len(s) == cap(s) == 1000
s := make([]int, 1&lt;&lt;63)         // illegal: len(s) is not representable by a value of type int
s := make([]int, 10, 0)         // illegal: len(s) > cap(s)
c := make(chan int, 10)         // channel with a buffer size of 10