* "12AB" is the four hexadecimal digits representing the 16-bit code unit.
   */
  private static String showCharacter(char c) {
    String hex = "0123456789ABCDEF";
    char[] tmp = {'\\', 'u', '\0', '\0', '\0', '\0'};
    for (int i = 0; i < 4; i++) {
      tmp[5 - i] = hex.charAt(c & 0xF);
      c = (char) (c >> 4);
    }
    return String.copyValueOf(tmp);
  }

  // Fast matchers

   * "12AB" is the four hexadecimal digits representing the 16-bit code unit.
   */
  private static String showCharacter(char c) {
    String hex = "0123456789ABCDEF";
    char[] tmp = {'\\', 'u', '\0', '\0', '\0', '\0'};
    for (int i = 0; i < 4; i++) {
      tmp[5 - i] = hex.charAt(c & 0xF);
      c = (char) (c >> 4);
    }
    return String.copyValueOf(tmp);
  }

  // Fast matchers

		}
	}
}

func TestQuoStepD6(t *testing.T) {
	// See Knuth, Volume 2, section 4.3.1, exercise 21. This code exercises
	// a code path which only triggers 1 in 10^{-19} cases.

	u := &Int{false, nat{0, 0, 1 + 1<<(_W-1), _M ^ (1 << (_W - 1))}}
	v := &Int{false, nat{5, 2 + 1<<(_W-1), 1 << (_W - 1)}}

	r := new(Int)
	q, r := new(Int).QuoRem(u, v, r)
	const expectedQ64 = "18446744073709551613"

func TestNoRestraint(t *testing.T) {
	metrics.Register()
	testCases := []struct {
		concurrency int
		margin      float64
		fair        bool
		name        string
	}{
		{concurrency: 10, margin: 0.001, fair: true, name: "no-competition"},
		{concurrency: 2, margin: 0.25, fair: false, name: "with-competition"},
	}
	for _, testCase := range testCases {
		t.Run(testCase.name, func(t *testing.T) {
			now := time.Now()

//
// By convention, tag strings are a concatenation of
// optionally space-separated key:"value" pairs.
// Each key is a non-empty string consisting of non-control
// characters other than space (U+0020 ' '), quote (U+0022 '"'),
// and colon (U+003A ':').  Each value is quoted using U+0022 '"'
// characters and Go string literal syntax.
type StructTag string

	{"%+10.2f", +104.66 - 440.51i, "(   +104.66   -440.51i)"},
	{"%+10.2f", -104.66 - 440.51i, "(   -104.66   -440.51i)"},
	{"%+010.2f", +104.66 + 440.51i, "(+000104.66+000440.51i)"},
	{"%+010.2f", -104.66 + 440.51i, "(-000104.66+000440.51i)"},
	{"%+010.2f", +104.66 - 440.51i, "(+000104.66-000440.51i)"},
	{"%+010.2f", -104.66 - 440.51i, "(-000104.66-000440.51i)"},

	// []T where type T is a byte with a Stringer method.

			{".ctors", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x600688, 0x688, 0x10, 0x0, 0x0, 0x8, 0x0, 0x10},
			{".dtors", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x600698, 0x698, 0x10, 0x0, 0x0, 0x8, 0x0, 0x10},
			{".jcr", SHT_PROGBITS, SHF_WRITE + SHF_ALLOC, 0x6006a8, 0x6a8, 0x8, 0x0, 0x0, 0x8, 0x0, 0x8},
			{".dynamic", SHT_DYNAMIC, SHF_WRITE + SHF_ALLOC, 0x6006b0, 0x6b0, 0x1a0, 0x6, 0x0, 0x8, 0x10, 0x1a0},

	if err != nil {
		return 0, 0, 0, buf, err
	}
	metaVer, buf, err := msgp.ReadUint8Bytes(buf)
	if err != nil {
		return 0, 0, 0, buf, err
	}
	if hdrVer > xlHeaderVersion {
		return 0, 0, 0, buf, fmt.Errorf("decodeXLHeaders: Unknown xl header version %d", metaVer)
	}
	if metaVer > xlMetaVersion {
		return 0, 0, 0, buf, fmt.Errorf("decodeXLHeaders: Unknown xl meta version %d", metaVer)
	}

const (
	// It doesn't really matter what value we start at, but we can't be zero, because
	// that'll cause divide-by-zero issues. Pick something conservative which we'll
	// also use as a fallback.
	startingScavSleepRatio = 0.001

	// Spend at least 1 ms scavenging, otherwise the corresponding
	// sleep time to maintain our desired utilization is too low to
	// be reliable.
	minScavWorkTime = 1e6
)

// CHECK:     %2:8 = "tfl.while"(%arg2, %arg2, %arg3, %arg4, %0, %0, %1, %1) ({