std::numeric_limits<T>::max_exponent

 

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static const int max_exponent;		(until C++11)
static constexpr int max_exponent;		(since C++11)

The value of std::numeric_limits<T>::max_exponent is the largest positive number n such that \(\scriptsize r^{n-1}\)rn-1
, where r is std::numeric_limits<T>::radix, is a representable finite value of the floating-point type T.

Standard specializations

T	value of std::numeric_limits<T>::max_exponent
/* non-specialized */	​0​
bool	​0​
char	​0​
signed char	​0​
unsigned char	​0​
wchar_t	​0​
char8_t (C++20)	​0​
char16_t (C++11)	​0​
char32_t (C++11)	​0​
short	​0​
unsigned short	​0​
int	​0​
unsigned int	​0​
long	​0​
unsigned long	​0​
long long (C++11)	​0​
unsigned long long (C++11)	​0​
float	FLT_MAX_EXP
double	DBL_MAX_EXP
long double	LDBL_MAX_EXP

Example

Demonstrates the relationships of max_exponent, max_exponent10, and max() for the type float:

Run this code

#include <iostream>
#include <limits>
int main()
{
    std::cout << "max() = " << std::numeric_limits<float>::max() << '\n'
              << "max_exponent10 = " << std::numeric_limits<float>::max_exponent10 << '\n'
              << std::hexfloat
              << "max() = " << std::numeric_limits<float>::max() << '\n'
              << "max_exponent = " << std::numeric_limits<float>::max_exponent << '\n';
}

Output:

max() = 3.40282e+38
max_exponent10 = 38
max() = 0x1.fffffep+127
max_exponent = 128

See also

min_exponent10 [static]	the smallest negative power of ten that is a valid normalized floating-point value (public static member constant)
min_exponent [static]	one more than the smallest negative power of the radix that is a valid normalized floating-point value (public static member constant)
max_exponent10 [static]	the largest integer power of 10 that is a valid finite floating-point value (public static member constant)