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(C++11)(until C++20)
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(C++11)(until C++20)(C++17)
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 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 0
char16_t 0
char32_t 0
short 0
unsigned short 0
int 0
unsigned int 0
long 0
unsigned long 0
long long 0
unsigned long long 0
double DBL_MAX_EXP
long double LDBL_MAX_EXP


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

#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';


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

See also

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