float:
	sizeof(float) =               4
	FLT_MANT_DIG =               24
	machine epsilon =             1.19209e-07  [IEEE 754 32-bit macheps]
	smallest positive number =    1.40130e-45  [IEEE 754 smallest 32-bit subnormal]

double:
	sizeof(double) =              8
	DBL_MANT_DIG =               53
	machine epsilon =             2.22045e-16  [IEEE 754 64-bit macheps]
	smallest positive number =   4.94066e-324  [IEEE 754 smallest 64-bit subnormal]

long double:
	sizeof(long double) =        16
	LDBL_MANT_DIG =             113
	machine epsilon =             1.92593e-34  [IEEE 754 128-bit macheps]
	smallest positive number =  6.47518e-4966  [IEEE 754 smallest 128-bit subnormal]