NAME

std::numeric_limits::min_exponent - std::numeric_limits::min_exponent

Synopsis

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
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_MIN_EXP
double DBL_MIN_EXP
long double LDBL_MIN_EXP

Example

Demonstrates the relationships of min_exponent, min_exponent10, min, and radix for
the type float:

// Run this code

#include <iostream>
int main()
{
std::cout << "min() = " << std::numeric_limits<float>::min() << '\n'
<< "min_exponent10 = " << std::numeric_limits<float>::min_exponent10 << '\n'
<< std::hexfloat
<< "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

radix the radix or integer base used by the representation of the given
[static] type
(public static member constant)
min_exponent10 the smallest negative power of ten that is a valid normalized
[static] floating-point value
(public static member constant)
max_exponent one more than the largest integer power of the radix that is a valid
[static] finite 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)