std::numeric_limits<T>::has_denorm

 

C++

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Feature test macros (C++20)

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符号索引

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实用工具库

语言支持 类型支持 (基本类型，RTTI) Library feature-test macros (C++20) 程序实用工具 可变参数函数 initializer_list (C++11) is_constant_evaluated (C++20) is_within_lifetime (C++26) source_location (C++20) Coroutine support (C++20) Contract support (C++26) 三路比较 three_way_comparablethree_way_comparable_with (C++20)(C++20) strong_ordering (C++20) weak_ordering (C++20) partial_ordering (C++20) common_comparison_category (C++20) compare_three_way_result (C++20) compare_three_way (C++20) strong_order (C++20) weak_order (C++20) partial_order (C++20) compare_strong_order_fallback (C++20) compare_weak_order_fallback (C++20) compare_partial_order_fallback (C++20)   is_eqis_ltis_lteq (C++20)(C++20)(C++20)   is_neqis_gtis_gteq (C++20)(C++20)(C++20)

通用实用工具 函数对象 Bit manipulation (C++20) bitset hash (C++11) Relational operators (deprecated in C++20) rel_ops::operator!=rel_ops::operator>    rel_ops::operator<=rel_ops::operator>= 整数比较函数 cmp_equalcmp_lesscmp_less_than (C++20)(C++20)(C++20)   cmp_not_equalcmp_greatercmp_greater_than (C++20)(C++20)(C++20) in_range (C++20) Swap 和 type operations swap ranges::swap (C++20) exchange (C++14) declval (C++11) to_underlying (C++23) forward (C++11) forward_like (C++23) move (C++11) move_if_noexcept (C++11) as_const (C++17) 通用词汇类型 pair tuple (C++11) optional (C++17) any (C++17) variant (C++17) tuple_size (C++11) tuple_element (C++11) apply (C++17) make_from_tuple (C++17) expected (C++23)

 

类型支持

基本类型
Fixed width integer types (C++11)
Fixed width floating-point types (C++23)
ptrdiff_t size_t max_align_t (C++11)     byte (C++17)	nullptr_t (C++11) offsetof NULL
数值限制
numeric_limits
C 数值限制接口
运行时类型信息
type_info type_index (C++11)	bad_typeid bad_cast

 

std::numeric_limits

静态常量

numeric_limits::is_specialized

numeric_limits::is_signed

numeric_limits::is_integer

numeric_limits::is_exact

numeric_limits::has_infinity

numeric_limits::has_quiet_NaN

numeric_limits::has_signaling_NaN

numeric_limits::has_denorm

numeric_limits::has_denorm_loss

numeric_limits::round_style

numeric_limits::is_iec559

numeric_limits::is_bounded

numeric_limits::is_modulo

numeric_limits::digits

numeric_limits::digits10

numeric_limits::max_digits10 (C++11)

numeric_limits::radix

numeric_limits::min_exponent

numeric_limits::min_exponent10

numeric_limits::max_exponent

numeric_limits::max_exponent10

numeric_limits::traps

numeric_limits::tinyness_before

静态成员函数

numeric_limits::min

numeric_limits::lowest (C++11)

numeric_limits::max

numeric_limits::epsilon

numeric_limits::round_error

numeric_limits::infinity

numeric_limits::quiet_NaN

numeric_limits::signaling_NaN

numeric_limits::denorm_min

辅助类型

float_round_style

float_denorm_style

 

static const std::float_denorm_style has_denorm;		(直到 C++11)
static constexpr std::float_denorm_style has_denorm;		(自 C++11 起) (在 C++23 中弃用)

std::numeric_limits<T>::has_denorm 的值标识了支持 subnormal values 的浮点类型。

标准特化

T	std::numeric_limits<T>::has_denorm 的值
/* 非特化 */	std::denorm_absent
bool	std::denorm_absent
char	std::denorm_absent
signed char	std::denorm_absent
unsigned char	std::denorm_absent
wchar_t	std::denorm_absent
char8_t (since C++20)	std::denorm_absent
char16_t (since C++11)	std::denorm_absent
char32_t (since C++11)	std::denorm_absent
short	std::denorm_absent
unsigned short	std::denorm_absent
int	std::denorm_absent
unsigned int	std::denorm_absent
long	std::denorm_absent
unsigned long	std::denorm_absent
long long (since C++11)	std::denorm_absent
unsigned long long (since C++11)	std::denorm_absent
float	通常为 std::denorm_present
double	通常为 std::denorm_present
long double	通常为 std::denorm_present

参见

denorm_min [静态]	返回给定浮点类型的最小正次正规值 (public static member function)
float_denorm_style	指示浮点反常化模式 (enum)