std::numeric_limits::denorm_min
static T denorm_min(); | | (until C++11) |
|---|---|---|
static constexpr T denorm_min(); | | (since C++11) |
返回最小正值亚正常值类型T，如果std::numeric_limits<T>::has_denorm!=std::denorm_absent，否则返回std::numeric_limits<T>::min().仅对浮点类型有意义.
返回值
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 */ |
例外
(none) | (until C++11) |
|---|---|
noexcept specification: noexcept | (since C++11) |
例
证明了deorm的基本位结构。[医]最低28%%29。
二次
#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());
}二次
另见
min static | returns the smallest finite value of the given type (public static member function) |
|---|---|
has_denorm static | identifies the denormalization style used by the floating-point type (public static member constant) |
lowest static | returns the lowest finite value of the given type (public static member function) |
© cppreference.com在CreativeCommonsAttribution下授权-ShareAlike未移植许可v3.0。
本文档系腾讯云开发者社区成员共同维护，如有问题请联系 cloudcommunity@tencent.com
