// 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) }

	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)
	}

		// 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.

// 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;

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.

</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

pkg syscall (freebsd-arm), const SYS_ACCEPT4 ideal-int
pkg syscall (freebsd-arm), const SYS_BINDAT = 538
pkg syscall (freebsd-arm), const SYS_BINDAT ideal-int
pkg syscall (freebsd-arm), const SYS_CAP_GETRIGHTS = 515
pkg syscall (freebsd-arm), const SYS_CAP_GETRIGHTS ideal-int
pkg syscall (freebsd-arm), const SYS_CHFLAGSAT = 540
pkg syscall (freebsd-arm), const SYS_CHFLAGSAT ideal-int
pkg syscall (freebsd-arm), const SYS_CONNECTAT = 539

pkg bufio, method (*Reader) Discard(int) (int, error)
pkg bufio, method (ReadWriter) Discard(int) (int, error)
pkg bytes, func LastIndexByte([]uint8, uint8) int
pkg bytes, method (*Buffer) Cap() int
pkg bytes, method (*Reader) Size() int64
pkg crypto, const SHA512_224 = 14
pkg crypto, const SHA512_224 Hash
pkg crypto, const SHA512_256 = 15
pkg crypto, const SHA512_256 Hash