std::numeric_limits::denorm_min
From cppreference.com
< cpp | types | numeric limits
| 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.
Contents |
[edit] 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 */ |
[edit] Exceptions
| (none) | (until C++11) |
| noexcept specification: noexcept |
(since C++11) |
[edit] Example
Demonstates the underlying bit structure of the denorm_min()
Run this code
#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()); }
[edit] 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) |