Standard C++ Library Reference ISO/IEC (VERSION3)

FLT_MIN_EXP
#define FLT_MIN_EXP <integer rvalue>
The macro yields the minimum integer X, such that FLT_RADIX^(X - 1) is a normalized, finite
representable value of type float.
FLT_RADIX
#define FLT_RADIX <#if expression >= 2>
The macro yields the radix of all floating-point representations.
FLT_ROUNDS
#define FLT_ROUNDS <integer rvalue>
The macro yields a value that describes the current rounding mode for floating-point operations.
Note that the target environment can change the rounding mode while the program executes.
How it does so, however, is not specified. The values are:
-1 if the mode is indeterminate●
0 if rounding is toward zero●
1 if rounding is to nearest representable value●
2 if rounding is toward positive infinity●
3 if rounding is toward negative infinity●
An implementation can define additional values for this macro.
LDBL_DIG
#define LDBL_DIG <integer rvalue >= 10>
The macro yields the precision in decimal digits for type long double.
LDBL_EPSILON
#define LDBL_EPSILON <long double rvalue <= 10^(-9)>
The macro yields the smallest X of type long double such that 1.0 + X != 1.0.