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std::numeric_limits::min_exponent

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Revision as of 08:05, 9 June 2013 by P12 (Talk | contribs)

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

The value of std::numeric_limits<T>::min_exponent10 is the lowest negative number n such that 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
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
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:

#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

[static]
the radix or integer base used by the representation of the given type
(public static member constant) [edit]
the smallest negative power of ten that is a valid normalized floating-point value
(public static member constant) [edit]
one more than the largest integer power of the radix that is a valid finite floating-point value
(public static member constant) [edit]
the largest integer power of 10 that is a valid finite floating-point value
(public static member constant) [edit]