W3cubDocs

/C++

std::numeric_limits<T>::max_exponent10

static const int max_exponent10;
(until C++11)
static constexpr int max_exponent10;
(since C++11)

The value of std::numeric_limits<T>::max_exponent10 is the largest positive number n such that \(\scriptsize 10^n\)10n
is a representable finite value of the floating-point type T.

Standard specializations

T value of std::numeric_limits<T>::max_exponent10
/* non-specialized */ ​0​
bool ​0​
char ​0​
signed char ​0​
unsigned char ​0​
wchar_t ​0​
char8_t (since C++20) ​0​
char16_t (since C++11) ​0​
char32_t (since C++11) ​0​
short ​0​
unsigned short ​0​
int ​0​
unsigned int ​0​
long ​0​
unsigned long ​0​
long long (since C++11) ​0​
unsigned long long (since C++11) ​0​
float FLT_MAX_10_EXP
double DBL_MAX_10_EXP
long double LDBL_MAX_10_EXP

Example

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 << '\n'
              << "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

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

© cppreference.com
Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.
https://en.cppreference.com/w/cpp/types/numeric_limits/max_exponent10