The header float.h contains macros that expand to various limits and parameters of the standard floating-point types.
The macros, as defined on ISO 9899:1999 section 188.8.131.52.2, are:
FLT_ROUNDS– indicates the rounding mode for floating-point addition, meaning:
2toward positive infinity;
3toward negative infinity;
- other value means implementation-defined rounding behavior.
FLT_EVAL_METHOD(C99) – determines the evaluation formats of expressions involving all floating types:
0evaluate all operations and constants just to the precision of the type;
1evaluate operations and constants of type float and double to the range and precision of the double type;
2evaluate all operations and constants to the range and precision of the long double type;
- other value means implementation-defined behavior.
FLT_RADIX– radix of exponent representation (at least
LDBL_MANT_DIG– number of digits in the floating-point significand.
DECIMAL_DIG(C99) – (at least
LDBL_DIG- (at least 6, 10, 10)
LDBL_MIN_10_EXP, (at least
LDBL_MAX– (Maximum value, at least
LDBL_EPSILON– (Machine epsilon, no greater than
LDBL_MIN– (no greater than
- The Single UNIX® Specification, Issue 7 from The Open Group : floating types – Base Definitions Reference,
- C++ reference for implementation defined numeric constants inherited from C