{"0x1.fffffffffffffp1023", math.MaxFloat64},

		// underscores
		{"0_0", 0},
		{"1_000.", 1000},
		{"1_2_3.4_5_6", 123.456},
		{"1.0e0_0", 1},
		{"1p+1_0", 1024},
		{"0b_1000", 0x8},
		{"0b_1011_1101", 0xbd},
		{"0x_f0_0d_1eP+0_8", 0xf00d1e00},
	} {
		var x Float
		x.SetPrec(53)
		_, ok := x.SetString(test.s)
		if math.IsNaN(test.x) {
			// test.s is invalid
			if ok {

	assert(0b0 == 0)
	assert(0b1011 == 0xb)
	assert(0b00101101 == 0x2d)

	assert(0B0 == 0)
	assert(0B1011 == 0xb)
	assert(0B00101101 == 0x2d)

	assert(0b_0 == 0)
	assert(0b10_11 == 0xb)
	assert(0b_0010_1101 == 0x2d)

	// decimal floats
	assert(1_2_3. == 123.)
	assert(0_123. == 123.)

	assert(0_0e0 == 0.)
	assert(1_2_3e0 == 123.)
	assert(0_123e0 == 123.)

	assert(0e-0_0 == 0.)
	assert(1_2_3E+0 == 123.)

	`0O0123_4567 = 01234567`,

	// binaries
	`0b0 = 0`,
	`0b1011 = 0xb`,
	`0b00101101 = 0x2d`,

	`0B0 = 0`,
	`0B1011 = 0xb`,
	`0B00101101 = 0x2d`,

	`0b_0 = 0`,
	`0b10_11 = 0xb`,
	`0b_0010_1101 = 0x2d`,
}

// The RHS operand may be a floating-point quotient n/d of two integer values n and d.
var floatTests = []string{
	// decimal floats
	`1_2_3. = 123.`,
	`0_123. = 123.`,

	`0_0e0 = 0.`,