},
		{
			name: "max",
			fields: fields{
				value: []byte(strconv.FormatFloat(math.MaxFloat64, 'g', -1, 64)),
			},
			want:   math.MaxFloat64,
			wantOK: true,
		},
		{
			name: "min",
			fields: fields{
				value: []byte(strconv.FormatFloat(-math.MaxFloat64, 'g', -1, 64)),
			},
			want:   -math.MaxFloat64,
			wantOK: true,
		},
		{
			name: "max-overflow",
			fields: fields{

// approximation of r.
// Returns true on success.
func checkIsBestApprox64(t *testing.T, f float64, r *Rat) bool {
	if math.Abs(f) >= math.MaxFloat64 {
		// Cannot check +Inf, -Inf, nor the float next to them (MaxFloat64).
		// But we have tests for these special cases.
		return true
	}

	// r must be strictly between f0 and f1, the floats bracketing f.
	f0 := math.Nextafter(f, math.Inf(-1))

// swap swaps the elements with indexes i and j.
func Shuffle(n int, swap func(i, j int)) { globalRand.Shuffle(n, swap) }

// NormFloat64 returns a normally distributed float64 in the range
// [-math.MaxFloat64, +math.MaxFloat64] with
// standard normal distribution (mean = 0, stddev = 1)
// from the default Source.
// To produce a different normal distribution, callers can
// adjust the output using:
//

func Read(p []byte) (n int, err error) { return globalRand().Read(p) }

// NormFloat64 returns a normally distributed float64 in the range
// [-[math.MaxFloat64], +[math.MaxFloat64]] with
// standard normal distribution (mean = 0, stddev = 1)
// from the default [Source].
// To produce a different normal distribution, callers can
// adjust the output using:
//

		return 0
	}

	sign := false
	if x < 0 {
		x = -x
		sign = true
	}
	if x >= 2 {
		s, c := Sincos(x)
		ss := -s - c
		cc := s - c

		// make sure x+x does not overflow
		if x < MaxFloat64/2 {
			z := Cos(x + x)
			if s*c > 0 {
				cc = z / ss
			} else {
				ss = z / cc
			}
		}

		// j1(x) = 1/sqrt(pi) * (P(1,x)*cc - Q(1,x)*ss) / sqrt(x)

	case IsInf(x, 0):
		return 0
	case x == 0:
		return 1
	}

	x = Abs(x)
	if x >= 2 {
		s, c := Sincos(x)
		ss := s - c
		cc := s + c

		// make sure x+x does not overflow
		if x < MaxFloat64/2 {
			z := -Cos(x + x)
			if s*c < 0 {
				cc = z / ss
			} else {
				ss = z / cc
			}
		}

		// j0(x) = 1/sqrt(pi) * (P(0,x)*cc - Q(0,x)*ss) / sqrt(x)

 * (Marsaglia & Tsang, 2000)
 * https://www.jstatsoft.org/v05/i08/paper [pdf]
 */

const (
	re = 7.69711747013104972
)

// ExpFloat64 returns an exponentially distributed float64 in the range
// (0, +math.MaxFloat64] with an exponential distribution whose rate parameter
// (lambda) is 1 and whose mean is 1/lambda (1).
// To produce a distribution with a different rate parameter,
// callers can adjust the output using:
//

 * (Marsaglia & Tsang, 2000)
 * https://www.jstatsoft.org/v05/i08/paper [pdf]
 */

const (
	re = 7.69711747013104972
)

// ExpFloat64 returns an exponentially distributed float64 in the range
// (0, +[math.MaxFloat64]] with an exponential distribution whose rate parameter
// (lambda) is 1 and whose mean is 1/lambda (1).
// To produce a distribution with a different rate parameter,
// callers can adjust the output using:
//

	if rand.Int()&1 == 1 {
		f = -f
	}
	return float32(f)
}

// randFloat64 generates a random float taking the full range of a float64.
func randFloat64(rand *rand.Rand) float64 {
	f := rand.Float64() * math.MaxFloat64
	if rand.Int()&1 == 1 {
		f = -f
	}
	return f
}

// randInt64 returns a random int64.
func randInt64(rand *rand.Rand) int64 {
	return int64(rand.Uint64())
}

	var zero float64
	for _, arg := range []float64{
		-math.MaxFloat32,
		-10,
		-0.5,
		-zero,
		zero,
		1,
		10,
		123456789.87654321e-23,
		1e10,
		math.MaxFloat64,
	} {
		val := MakeFloat64(arg)
		if val.Kind() != Float {
			t.Errorf("%v: got kind = %d; want %d", arg, val.Kind(), Float)
		}

		// -0.0 is mapped to 0.0
		got, exact := Float64Val(val)