Numeric limits

Defined in header <stdint.h>
PTRDIFF_MIN (C99)	minimum value of object of ptrdiff_t type (macro constant)
PTRDIFF_MAX (C99)	maximum value of object of ptrdiff_t type (macro constant)
SIZE_MAX (C99)	maximum value of object of size_t type (macro constant)
SIG_ATOMIC_MIN (C99)	maximum value of object of sig_atomic_t type (macro constant)
SIG_ATOMIC_MAX (C99)	maximum value of object of sig_atomic_t type (macro constant)
WCHAR_MIN (C99)	maximum value of object of wchar_t type (macro constant)
WCHAR_MAX (C99)	maximum value of object of wchar_t type (macro constant)
WINT_MIN (C99)	maximum value of object of wint_t type (macro constant)
WINT_MAX (C99)	maximum value of object of wint_t type (macro constant)

Limits of integer types

Defined in header <limits.h>
CHAR_BIT	number of bits in byte (macro constant)
MB_LEN_MAX	maximum number of bytes in a multibyte character (macro constant)
CHAR_MIN	minimum value of char (macro constant)
CHAR_MAX	maximum value of char (macro constant)
SCHAR_MIN SHRT_MIN INT_MIN LONG_MIN LLONG_MIN (C99)	minimum value of signed char, short, int, long and long long respectively (macro constant)
SCHAR_MAX SHRT_MAX INT_MAX LONG_MAX LLONG_MAX (C99)	maximum value of signed char, short, int, long and long long respectively (macro constant)
UCHAR_MAX USHRT_MAX UINT_MAX ULONG_MAX ULLONG_MAX (C99)	maximum value of unsigned char, unsigned short, unsigned int, unsigned long and unsigned long long respectively (macro constant)

Limits of floating point types

Defined in header <float.h>
FLT_RADIX	the radix (integer base) used by the representation of all three floating-point types (macro constant)
DECIMAL_DIG (C99)	number of decimal digits that can be converted to long double and back without losing precision (macro constant)
FLT_MIN DBL_MIN LDBL_MIN	minimum value of float, double and long double respectively (macro constant)
FLT_MAX DBL_MAX LDBL_MAX	maximum value of float, double and long double respectively (macro constant)
FLT_EPSILON DBL_EPSILON LDBL_EPSILON	difference between 1.0 and the next representable value for float, double and long double respectively (macro constant)
FLT_DIG DBL_DIG LDBL_DIG	number of decimal digits that can be represented without losing precision for float, double and long double respectively (macro constant)
FLT_MANT_DIG DBL_MANT_DIG LDBL_MANT_DIG	number of base FLT_RADIX digits that can be represented without losing precision for float, double and long double respectively (macro constant)
FLT_MIN_EXP DBL_MIN_EXP LDBL_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_EXP DBL_MIN_10_EXP LDBL_MIN_10_EXP	minimum negative integer such that 10 raised by power one less than that integer is a normalized float, double and long double respectively (macro constant)
FLT_MAX_EXP DBL_MAX_EXP LDBL_MAX_EXP	maximum positive integer such that FLT_RADIX raised by power one more than that integer is a normalized float, double and long double respectively (macro constant)
FLT_MAX_10_EXP DBL_MAX_10_EXP LDBL_MAX_10_EXP	maximum positive integer such that 10 raised by power one more than that integer is a normalized float, double and long double respectively (macro constant)
FLT_ROUNDS	rounding mode of floating-point arithmetics, equal to float_round_style (macro constant)
FLT_EVAL_METHOD (C99)	use of extended precision for intermediate results: 0 not used, 1 double is used instead of float, 2: long double is used (macro constant)