Standard library header <float.h> - cppreference.com (original) (raw)
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) |
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| 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) |
| FLT_ROUNDS | rounding mode of floating-point arithmetic (macro constant) |
| FLT_EVAL_METHOD(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) |
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[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 */