std::numeric_limits::digits
From cppreference.com
< cpp | types | numeric limits
| static const int digits |
(until C++11) | |
| static constexpr int digits |
(since C++11) | |
The value of std::numeric_limits<T>::digits is the number of digits in base-radix that can be represented by the type T without change. For integer types, this is the number of bits not counting the sign bit. For floating-point types, this is the number of digits in the mantissa.
[edit] Standard specializations
| T | value of std::numeric_limits<T>::digits |
| /* non-specialized */ | 0 |
| bool | 1 |
| char | CHAR_BIT - std::numeric_limits<char>::is_signed |
| signed char | CHAR_BIT-1 |
| unsigned char | CHAR_BIT |
| wchar_t | CHAR_BIT*sizeof(wchar_t) - std::numeric_limits<wchar_t>::is_signed |
| char16_t | CHAR_BIT*sizeof(char16_t) |
| char32_t | CHAR_BIT*sizeof(char32_t) |
| short | CHAR_BIT*sizeof(short)-1 |
| unsigned short | CHAR_BIT*sizeof(short) |
| int | CHAR_BIT*sizeof(int)-1 |
| unsigned int | CHAR_BIT*sizeof(int) |
| long | CHAR_BIT*sizeof(long)-1 |
| unsigned long | CHAR_BIT*sizeof(long) |
| long long | CHAR_BIT*sizeof(long long)-1 |
| unsigned long long | CHAR_BIT*sizeof(long) |
| float | FLT_MANT_DIG |
| double | DBL_MANT_DIG |
| long double | LDBL_MANT_DIG |
[edit] See also
| [static] |
the radix or integer base used by the representation of the given type (public static member constant) |
| [static] |
one more than the smallest negative power of the radix that is a valid normalized floating-point value (public static member constant) |
| [static] |
one more than the largest integer power of the radix that is a valid finite floating-point value (public static member constant) |
