Standard library header <float.h>
From cppreference.com
This header is part of the type support library, in particular its numeric limits interface.
[edit] Macros
| FLT_RADIX |
the radix (integer base) used by the representation of all three floating-point types (macro constant) |
| DECIMAL_DIG (C99) |
conversion from long double to decimal with at least DECIMAL_DIG digits and back to long double is the identity conversion: this is the decimal precision required to serialize/deserialize a long double (macro constant) |
| FLT_DECIMAL_DIGDBL_DECIMAL_DIGLDBL_DECIMAL_DIG (C11) |
conversion from float/double/long double to decimal with at least FLT_DECIMAL_DIG/DBL_DECIMAL_DIG/LDBL_DECIMAL_DIG digits and back is the identity conversion: this is the decimal precision required to serialize/deserialize a floating-point value. Defined to at least 6, 10, and 10 respectively, or 9 for IEEE float and 17 for IEEE double (see also the C++ analog: max_digits10) (macro constant) |
| FLT_MINDBL_MINLDBL_MIN |
minimum, normalized, positive value of float, double and long double respectively (macro constant) |
| FLT_TRUE_MINDBL_TRUE_MINLDBL_TRUE_MIN (C11) |
minimum positive value of float, double and long double respectively (macro constant) |
| FLT_MAXDBL_MAXLDBL_MAX |
maximum finite value of float, double and long double respectively (macro constant) |
| FLT_EPSILONDBL_EPSILONLDBL_EPSILON |
absolute value difference between 1.0 and the next representable value for float, double and long double respectively (macro constant) |
| FLT_DIGDBL_DIGLDBL_DIG |
number of decimal digits that are guaranteed to be preserved in text → float/double/long double → text roundtrip without change due to rounding or overflow (see the C++ analog digits10 for detail) (macro constant) |
| FLT_MANT_DIGDBL_MANT_DIGLDBL_MANT_DIG |
number of base-FLT_RADIX digits that are in the floating-point mantissa and that can be represented without losing precision for float, double and long double respectively (macro constant) |
| FLT_MIN_EXPDBL_MIN_EXPLDBL_MIN_EXP |
minimum negative integer such that FLT_RADIX raised by power one less than that integer is a normalized float, double and long double respectively (macro constant) |
| FLT_MIN_10_EXPDBL_MIN_10_EXPLDBL_MIN_10_EXP |
minimum negative integer such that 10 raised to that power is a normalized float, double and long double respectively (macro constant) |
| FLT_MAX_EXPDBL_MAX_EXPLDBL_MAX_EXP |
maximum positive integer such that FLT_RADIX raised by power one less than that integer is a representable finite float, double and long double respectively (macro constant) |
| FLT_MAX_10_EXPDBL_MAX_10_EXPLDBL_MAX_10_EXP |
maximum positive integer such that 10 raised to that power is a representable finite float, double and long double respectively (macro constant) |
| rounding mode of floating-point arithmetic (macro constant) | |
| (C99) |
specifies in what precision all arithmetic operations are done (macro constant) |
| FLT_HAS_SUBNORMDBL_HAS_SUBNORMLDBL_HAS_SUBNORM (C11)(deprecated in C23) |
whether the type supports subnormal (denormal) numbers: -1 – indeterminable, 0 – absent, 1 – present (macro constant) |
| This section is incomplete Reason: Add macros from B.6.2, B.6.3 |
[edit] Synopsis
#define FLT_ROUNDS /* see definition */ #define FLT_EVAL_METHOD /* see definition */ #define FLT_HAS_SUBNORM /* see definition */ #define DBL_HAS_SUBNORM /* see definition */ #define LDBL_HAS_SUBNORM /* see definition */ #define FLT_RADIX /* see definition */ #define FLT_MANT_DIG /* see definition */ #define DBL_MANT_DIG /* see definition */ #define LDBL_MANT_DIG /* see definition */ #define FLT_DECIMAL_DIG /* see definition */ #define DBL_DECIMAL_DIG /* see definition */ #define LDBL_DECIMAL_DIG /* see definition */ #define DECIMAL_DIG /* see definition */ #define FLT_DIG /* see definition */ #define DBL_DIG /* see definition */ #define LDBL_DIG /* see definition */ #define FLT_MIN_EXP /* see definition */ #define DBL_MIN_EXP /* see definition */ #define LDBL_MIN_EXP /* see definition */ #define FLT_MIN_10_EXP /* see definition */ #define DBL_MIN_10_EXP /* see definition */ #define LDBL_MIN_10_EXP /* see definition */ #define FLT_MAX_EXP /* see definition */ #define DBL_MAX_EXP /* see definition */ #define LDBL_MAX_EXP /* see definition */ #define FLT_MAX_10_EXP /* see definition */ #define DBL_MAX_10_EXP /* see definition */ #define LDBL_MAX_10_EXP /* see definition */ #define FLT_MAX /* see definition */ #define DBL_MAX /* see definition */ #define LDBL_MAX /* see definition */ #define FLT_EPSILON /* see definition */ #define DBL_EPSILON /* see definition */ #define LDBL_EPSILON /* see definition */ #define FLT_MIN /* see definition */ #define DBL_MIN /* see definition */ #define LDBL_MIN /* see definition */ #define FLT_TRUE_MIN /* see definition */ #define DBL_TRUE_MIN /* see definition */ #define LDBL_TRUE_MIN /* see definition */
