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std::numeric_limits::denorm_min

static T denorm_min();
(until C++11)
static constexpr T denorm_min();
(since C++11)

Returns the minimum positive subnormal value of the type T, if std::numeric_limits<T>::has_denorm != std::denorm_absent, otherwise returns std::numeric_limits<T>::min(). Only meaningful for floating-point types.

Return value

T std::numeric_limits<T>::denorm_min()
/* non-specialized */ T();
bool false
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 2-149
if std::numeric_limits<float>::is_iec559 == true
double 2-1074
if std::numeric_limits<double>::is_iec559 == true
long double /* implementation-defined */

Exceptions

(none) (until C++11)
noexcept specification:
noexcept
(since C++11)

Example

Demonstates the underlying bit structure of the denorm_min().

#include <cstdint>
#include <limits>
#include <cassert>
int main()
{
    // the smallest subnormal value has sign bit = 0, exponent = 0
    // and only the least significant bit of the fraction is 1
    uint32_t denorm_bits = 0x0001;
    float denorm_float = reinterpret_cast<float&>(denorm_bits);
    assert(denorm_float == std::numeric_limits<float>::denorm_min());
}

See also

[static]
returns the smallest finite value of the given type
(public static member function)
[static]
identifies the denormalization style used by the floating-point type
(public static member constant)
[static] (C++11)
returns the lowest finite value of the given type
(public static member function)

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