std::numeric_limits::radix(3)

NAME
std::numeric_limits::radix - std::numeric_limits::radix

Synopsis
   static const int radix; (until C++11)
   static constexpr int radix; (since C++11)
   The value of std::numeric_limits<T>::radix is the base of the number system used in
   the representation of the type. It is 2 for all binary numeric types, but it may be,
   for example, 10 for IEEE 754 decimal floating-point types or for third-party
   binary-coded decimal integers. This constant is meaningful for all specializations.

Standard specializations
   T value of std::numeric_limits<T>::radix
   /* non-specialized */ 0
   bool 2
   char 2
   signed char 2
   unsigned char 2
   wchar_t 2
   char8_t (C++20) 2
   char16_t (C++11) 2
   char32_t (C++11) 2
   short 2
   unsigned short 2
   int 2
   unsigned int 2
   long 2
   unsigned long 2
   long long (C++11) 2
   unsigned long long (C++11) 2
   float FLT_RADIX
   double FLT_RADIX
   long double FLT_RADIX

See also
   digits number of radix digits that can be represented without change
   [static] (public static member constant)
   min_exponent one more than the smallest negative power of the radix that is a valid
   [static] normalized floating-point value
                (public static member constant)
   max_exponent one more than the largest integer power of the radix that is a valid
   [static] finite floating-point value
                (public static member constant)