std::numeric_limits<T>::min_exponent
static const int min_exponent; | (until C++11) | |
static constexpr int min_exponent; | (since C++11) |
The value of std::numeric_limits<T>::min_exponent is the lowest negative number n such that \(\scriptsize r^{n-1}\)rn-1, where r is std::numeric_limits<T>::radix, is a valid normalized value of the floating-point type T.
Standard specializations
T | value of std::numeric_limits<T>::min_exponent |
|---|---|
| /* non-specialized */ |
0 |
| bool |
0 |
| char |
0 |
| signedchar |
0 |
| unsignedchar |
0 |
| wchar_t |
0 |
| char8_t (since C++20) |
0 |
| char16_t (since C++11) |
0 |
| char32_t (since C++11) |
0 |
| short |
0 |
| unsignedshort |
0 |
| int |
0 |
| unsignedint |
0 |
| long |
0 |
| unsignedlong |
0 |
| longlong (since C++11) |
0 |
| unsignedlonglong (since C++11) |
0 |
| float |
FLT_MIN_EXP |
| double |
DBL_MIN_EXP |
| longdouble |
LDBL_MIN_EXP |
Example
Demonstrates the relationships of min_exponent, min_exponent10, min(), and radix for the type float:
#include <iostream>
#include <limits>
int main()
{
std::cout << "min() = " << std::numeric_limits<float>::min() << '\n'
<< "min_exponent10 = " << std::numeric_limits<float>::min_exponent10 << '\n'
<< std::hexfloat << '\n'
<< "min() = " << std::numeric_limits<float>::min() << '\n'
<< "min_exponent = " << std::numeric_limits<float>::min_exponent << '\n';
}
Output:
min() = 1.17549e-38 min_exponent10 = -37 min() = 0x1p-126 min_exponent = -125
See also
|
[static] | the radix or integer base used by the representation of the given type (public static member constant) |
|
[static] | the smallest negative power of ten that is a valid normalized floating-point value (public static member constant) |
|
[static] | one more than the largest integer power of the radix that is a valid finite 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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https://en.cppreference.com/cpp/types/numeric_limits/min_exponent
