copy(dst, src []T) int
copy(dst []byte, src string) int
</pre>

<p>
Examples:
</p>

<pre>
var a = [...]int{0, 1, 2, 3, 4, 5, 6, 7}
var s = make([]int, 6)
var b = make([]byte, 5)
n1 := copy(s, a[0:])            // n1 == 6, s == []int{0, 1, 2, 3, 4, 5}
n2 := copy(s, s[2:])            // n2 == 4, s == []int{2, 3, 4, 5, 4, 5}
n3 := copy(b, "Hello, World!")  // n3 == 5, b == []byte("Hello")
</pre>

    assertPermutationsCount(6, Collections2.permutations(newArrayList(1, 2, 3)));
    assertPermutationsCount(5040, Collections2.permutations(newArrayList(1, 2, 3, 4, 5, 6, 7)));
    assertPermutationsCount(40320, Collections2.permutations(newArrayList(1, 2, 3, 4, 5, 6, 7, 8)));
  }

  public void testPermutationSetSizeOverflow() {
    // 13 elements overflow an int
    assertEquals(
        Integer.MAX_VALUE,

	"127.1",
	// IPv4 field has value >255.
	"192.168.300.1",
	// IPv4 with too many fields.
	"192.168.0.1.5.6",
	// IPv6 with not enough fields.
	"1:2:3:4:5:6:7",
	// IPv6 with too many fields.
	"1:2:3:4:5:6:7:8:9",
	// IPv6 with 8 fields and a :: expander.
	"1:2:3:4::5:6:7:8",
	// IPv6 with a field bigger than 2b.
	"fe801::1",
	// IPv6 with non-hex values in field.
	"fe80:tail:scal:e::",

	{string(rune(28)), false},
	{string(rune(29)), false},
	{string(rune(30)), false},
	{string(rune(31)), false},
	{string(rune(0x7F)), false},
	{`' !"#$%&'()*+,-./:;<=>?@[\]^_{|}~`, true},
	{`0123456789`, true},
	{`ABCDEFGHIJKLMNOPQRSTUVWXYZ`, true},
	{`abcdefghijklmnopqrstuvwxyz`, true},
	{`☺`, true},
	{"\x80", false},
	{"a\xe0\xa0z", false},
	{"\ufeffabc", false},
	{"a\ufeffz", false},
}

}

var tests = []struct {
	filename string
	source   []byte // may be nil
	size     int
	lines    []int
}{
	{"a", []byte{}, 0, []int{}},
	{"b", []byte("01234"), 5, []int{0}},
	{"c", []byte("\n\n\n\n\n\n\n\n\n"), 9, []int{0, 1, 2, 3, 4, 5, 6, 7, 8}},
	{"d", nil, 100, []int{0, 5, 10, 20, 30, 70, 71, 72, 80, 85, 90, 99}},
	{"e", nil, 777, []int{0, 80, 100, 120, 130, 180, 267, 455, 500, 567, 620}},

func TestBasicEncoderDecoder(t *testing.T) {
	var values = []any{
		true,
		int(123),
		int8(123),
		int16(-12345),
		int32(123456),
		int64(-1234567),
		uint(123),
		uint8(123),
		uint16(12345),
		uint32(123456),
		uint64(1234567),
		uintptr(12345678),
		float32(1.2345),
		float64(1.2345678),
		complex64(1.2345 + 2.3456i),
		complex128(1.2345678 + 2.3456789i),
		[]byte("hello"),
		string("hello"),
	}

	digits := "0123456789_"
	if l.accept("0") {
		// Note: Leading 0 does not mean octal in floats.
		if l.accept("xX") {
			digits = "0123456789abcdefABCDEF_"
		} else if l.accept("oO") {
			digits = "01234567_"
		} else if l.accept("bB") {
			digits = "01_"
		}
	}
	l.acceptRun(digits)
	if l.accept(".") {
		l.acceptRun(digits)
	}
	if len(digits) == 10+1 && l.accept("eE") {
		l.accept("+-")

		t.Skip("Too slow on wasm")
	}
	if testing.Short() {
		t.Skip("Skipping in short mode")
	}
	testenv.ParallelOn64Bit(t)
	h := newHashSet()
	permutation(t, h, []uint32{0, 1, 2, 3, 4, 5, 6, 7}, 8)
	permutation(t, h, []uint32{0, 1 << 29, 2 << 29, 3 << 29, 4 << 29, 5 << 29, 6 << 29, 7 << 29}, 8)
	permutation(t, h, []uint32{0, 1}, 20)
	permutation(t, h, []uint32{0, 1 << 31}, 20)

	{"-0_1_2_3_4_5", 0, -012345, nil}, // octal
	{"0_1_2_3_4_5", 0, 012345, nil},   // octal
	{"-_012345", 0, 0, ErrSyntax},
	{"_-012345", 0, 0, ErrSyntax},
	{"_012345", 0, 0, ErrSyntax},
	{"0__12345", 0, 0, ErrSyntax},
	{"01234__5", 0, 0, ErrSyntax},
	{"012345_", 0, 0, ErrSyntax},

	{"+0xf", 0, 0xf, nil},
	{"-0xf", 0, -0xf, nil},
	{"0x+f", 0, 0, ErrSyntax},
	{"0x-f", 0, 0, ErrSyntax},
}

	}{
		{registry.DWORD, "Dword1", nil},
		{registry.DWORD, "Dword2", []byte{1, 2, 3}},
		{registry.QWORD, "Qword1", nil},
		{registry.QWORD, "Qword2", []byte{1, 2, 3}},
		{registry.QWORD, "Qword3", []byte{1, 2, 3, 4, 5, 6, 7}},
		{registry.MULTI_SZ, "MultiString1", nil},
		{registry.MULTI_SZ, "MultiString2", []byte{0}},
		{registry.MULTI_SZ, "MultiString3", []byte{'a', 'b', 0}},