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.
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 (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_EXP |
| 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 << '\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
|
[static] | the smallest negative power of ten that is a valid normalized 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 largest integer power of 10 that is a valid finite floating-point value (public static member constant) |
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