C numeric limits interface
From cppreference.com
                    
                                        
                    
                    
                                                            
                    See also std::numeric_limits interface.
| Defined in header  <cstdint> | |
| PTRDIFF_MIN (C++11) | minimum value of object of std::ptrdiff_t type (macro constant) | 
| PTRDIFF_MAX (C++11) | maximum value of object of std::ptrdiff_t type (macro constant) | 
| SIZE_MAX (C++11) | maximum value of object of std::size_t type (macro constant) | 
| SIG_ATOMIC_MIN (C++11) | minimum value of object of std::sig_atomic_t type (macro constant) | 
| SIG_ATOMIC_MAX (C++11) | maximum value of object of std::sig_atomic_t type (macro constant) | 
| WCHAR_MIN (C++11) | minimum value of object of wchar_t type (macro constant) | 
| WCHAR_MAX (C++11) | maximum value of object of wchar_t type (macro constant) | 
| WINT_MIN (C++11) | minimum value of object of std::wint_t type (macro constant) | 
| WINT_MAX (C++11) | maximum value of object of std::wint_t type (macro constant) | 
[edit] Limits of integer types
| Defined in header  <climits> | |
| 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_MINSHRT_MININT_MINLONG_MINLLONG_MIN (C++11) | minimum value of signed char, short, int, long and long long respectively (macro constant) | 
| SCHAR_MAXSHRT_MAXINT_MAXLONG_MAXLLONG_MAX (C++11) | maximum value of signed char, short, int, long and long long respectively (macro constant) | 
| UCHAR_MAXUSHRT_MAXUINT_MAXULONG_MAXULLONG_MAX (C++11) | maximum value of unsigned char, unsigned short, unsigned int, unsigned long and unsigned long long respectively (macro constant) | 
Note: the types of these constants, other than CHAR_BIT and MB_LEN_MAX, are required to match the results of the integral promotions as applied to objects of the types they describe: CHAR_MAX may have type int or unsigned int, but never char. Similarly USHRT_MAX may not be of an unsigned type: its type may be int.
[edit] Limits of floating point types
| Defined in header  <cfloat> | |
| FLT_RADIX | the radix (integer base) used by the representation of all three  floating-point types (macro constant) | 
| DECIMAL_DIG (C++11) | conversion from long double to decimal with at least DECIMAL_DIGdigits and back to long double is the identity conversion. : this is the decimal precision required to serialize/deserialize a long double (see also std::numeric_limits::max_digits10)(macro constant) | 
| FLT_DECIMAL_DIGDBL_DECIMAL_DIGLDBL_DECIMAL_DIG (C++17) | conversion from float/double/long double to decimal with at least FLT_DECIMAL_DIG/DBL_DECIMAL_DIG/LDBL_DECIMAL_DIGdigits and back is the identity conversion. : this is the decimal precision required to serialize/deserialize a floating-point value (see also std::numeric_limits::max_digits10). Defined to at least 6, 10, and 10 respectively, or 9 for IEEE float and 17 for IEEE double.(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 (C++17) | minimum positive value of float, double and long double respectively (macro constant) | 
| FLT_MAXDBL_MAXLDBL_MAX | maximum value of float, double and long double respectively (macro constant) | 
| FLT_EPSILONDBL_EPSILONLDBL_EPSILON | 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 std::numeric_limits::digits10 for explanation) (macro constant) | 
| FLT_MANT_DIGDBL_MANT_DIGLDBL_MANT_DIG | number of base FLT_RADIXdigits 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_RADIXraised 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 by power one less than that integer is a normalized float, double and long double respectively (macro constant) | 
| FLT_MAX_EXPDBL_MAX_EXPLDBL_MAX_EXP | maximum positive integer such that FLT_RADIXraised by power one more than that integer is a normalized 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 by power one more than that integer is a normalized float, double and long double respectively (macro constant) | 
| default rounding mode of floating-point arithmetics (macro constant) | |
| (C++11) | specifies in what precision all arithmetic operations are done (macro constant) | 
| FLT_HAS_SUBNORMDBL_HAS_SUBNORMLDBL_HAS_SUBNORM (C++17) | specifies whether the type supports subnormal (denormal) numbers: -1 indeterminable, 0 absent, 1 present (macro constant) | 


