NAME

std::numeric_limits::max_exponent - std::numeric_limits::max_exponent

Synopsis

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