std::numeric_limits

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C++
 
实用工具库
类型的支持 (basic types, RTTI, type traits)
动态内存管理
错误处理
程序实用工具
可变参数函数
日期和时间
函数对象
initializer_list（C++11）
bitset
hash（C++11）
关系运算符
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Relational operators
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rel_ops::operator!=
rel_ops::operator>
rel_ops::operator<=
rel_ops::operator>=
双和元组
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Pairs and tuples
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pair
tuple（C++11）
piecewise_construct_t（C++11）
piecewise_construct（C++11）
掉期，远期和移动
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Swap, forward and move
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swap
forward（C++11）
move（C++11）
move_if_noexcept（C++11）
declval（C++11）
 
类型的支持
基本类型
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Basic types
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基本类型
固定宽度的整数类型 （C++11）
nullptr_t（C++11）
offsetof
NULL
数值范围内
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Numeric limits
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numeric_limits
C数字限制接口
运行时类型信息
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Runtime type information
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type_info
type_index（C++11）
类型特征
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Type traits
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初级型两类
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Primary type categories
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is_void（C++11）
is_array（C++11）
is_pointer（C++11）
is_enum（C++11）
is_union（C++11）
is_class（C++11）
is_function（C++11）
is_object（C++11）
is_scalar（C++11）
is_compound（C++11）
is_integral（C++11）
is_floating_point（C++11）
is_fundamental（C++11）
is_arithmetic（C++11）
is_reference（C++11）
is_lvalue_reference（C++11）
is_rvalue_reference（C++11）
is_member_pointer（C++11）
is_member_object_pointer（C++11）
is_member_function_pointer（C++11）
类型属性
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Type properties
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is_const（C++11）
is_volatile（C++11）
is_pod（C++11）
is_empty（C++11）
is_polymorphic（C++11）
is_abstract（C++11）
is_trivial（C++11）
is_trivially_copyable（C++11）
is_standard_layout（C++11）
is_literal_type（C++11）
is_signed（C++11）
is_unsigned（C++11）
支持的操作
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Supported operations
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is_constructible
is_trivially_constructible
is_nothrow_constructible		（C++11）
（C++11）
（C++11）
is_default_constructible
is_trivially_default_constructible
is_nothrow_default_constructible		（C++11）
（C++11）
（C++11）
is_copy_constructible
is_trivially_copy_constructible
is_nothrow_copy_constructible		（C++11）
（C++11）
（C++11）
is_move_constructible
is_trivially_move_constructible
is_nothrow_move_constructible		（C++11）
（C++11）
（C++11）
is_assignable
is_trivially_assignable
is_nothrow_assignable		（C++11）
（C++11）
（C++11）
is_copy_assignable
is_trivially_copy_assignable
is_nothrow_copy_assignable		（C++11）
（C++11）
（C++11）
is_move_assignable
is_trivially_move_assignable
is_nothrow_move_assignable		（C++11）
（C++11）
（C++11）
is_destructible
is_trivially_destructible
is_nothrow_destructible		（C++11）
（C++11）
（C++11）
has_virtual_destructor（C++11）
关系和属性查询
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Relationships and property queries
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is_same（C++11）
is_base_of（C++11）
is_convertible（C++11）
alignment_of（C++11）
rank（C++11）
extent（C++11）
类型的修改
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Type modifications
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remove_cv
remove_const
remove_volatile		（C++11）
（C++11）
（C++11）
add_cv
add_const
add_volatile		（C++11）
（C++11）
（C++11）
make_signed（C++11）
make_unsigned（C++11）
remove_reference（C++11）
add_lvalue_reference
add_rvalue_reference		（C++11）
（C++11）
remove_pointer（C++11）
add_pointer（C++11）
remove_extent（C++11）
remove_all_extents（C++11）
类型转换
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Type transformations
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aligned_storage（C++11）
aligned_union（C++11）
decay（C++11）
enable_if（C++11）
conditional（C++11）
common_type（C++11）
underlying_type（C++11）
result_of（C++11）
键入特征常数
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Type trait constants
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integral_constant（C++11）
 
std::numeric_limits
静态常量
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Static constants
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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
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Static member functions
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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
助手类型
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Helper types
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float_round_style
float_denorm_style
 
Defined in header <limits>
template< class T > class numeric_limits;
numeric_limits类模板提供了一个标准化的方式来查询各种基本类型（如最大可能值类型int是std::numeric_limits<int>::max()）.
Original:
The numeric_limits class template provides a standardized way to query various properties of fundamental types (e.g. the largest possible value for type int is std::numeric_limits<int>::max()).
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此信息是通过专业的numeric_limits模板。标准库提供的所有基本类型的专业
Original:
This information is provided via specializations of the numeric_limits template. The standard library makes available specializations for all fundamental types:
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Defined in header <limits>
template<> class numeric_limits<bool>;

template<> class numeric_limits<char>;
template<> class numeric_limits<signed char>;
template<> class numeric_limits<unsigned char>;
template<> class numeric_limits<wchar_t>;
template<> class numeric_limits<char16_t>;   // C++11 feature
template<> class numeric_limits<char32_t>;   // C++11 feature
template<> class numeric_limits<short>;
template<> class numeric_limits<unsigned short>;
template<> class numeric_limits<int>;
template<> class numeric_limits<unsigned int>;
template<> class numeric_limits<long>;
template<> class numeric_limits<unsigned long>;
template<> class numeric_limits<long long>;
template<> class numeric_limits<unsigned long long>;
template<> class numeric_limits<float>;
template<> class numeric_limits<double>;

template<> class numeric_limits<long double>;
此外，每一个品种合格的每个基本类型的版本存在一个专业化，相同的不合格的专业化，例如： std::numeric_limits<const int>，std::numeric_limits<volatile int>，和std::numeric_limits<const volatile int>中所提供，并且相当于std::numeric_limits<int>.
Original:
Additionally, a specialization exists for every cv-qualified version of each fundamental type, identical to the unqualified specialization, e.g. std::numeric_limits<const int>, std::numeric_limits<volatile int>, and std::numeric_limits<const volatile int> are provided and are equivalent to std::numeric_limits<int>.
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标准库类型是基本类型（如std::size_t或std::streamsize还可以std::numeric_limits型性状进行审查，.
Original:
The standard library types that are aliases of fundamental types (such as std::size_t or std::streamsize may also be examined with the std::numeric_limits type traits.
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实现可以提供专业的std::numeric_limits为实现特定的类型：，例如GCC提供std::numeric_limits<__int128>。图书馆可以添加专业的别名库提供的类型，例如，一个16位的浮点类型OpenEXR提供了std::numeric_limits<half>
Original:
Implementations may provide specializations of std::numeric_limits for implementation-specific types: e.g. GCC provides std::numeric_limits<__int128>. Libraries may add specializations for library-provided types, e.g. OpenEXR provides std::numeric_limits<half> for a 16-bit floating-point type.
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目录

[编辑] 会员常数

[静态的] </ SPAN></div></div>
std::numeric_limits是一家专业的标识类型
Original:
identifies types for which std::numeric_limits is specialized
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识别符号类型
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identifies signed types
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确定整数类型
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identifies integer types
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确定确切类型
Original:
identifies exact types
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确定浮点类型，可以代表特殊值“正无穷大”
Original:
identifies floating-point types that can represent the special value "positive infinity"
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确定浮点类型，可以代表特殊值“安静的不是一个数字”（NaN）
Original:
identifies floating-point types that can represent the special value "quiet not-a-number" (NaN)
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确定浮点类型可以代表的特殊价值“不是一个数字”（NaN）的信号
Original:
identifies floating-point types that can represent the special value "signaling not-a-number" (NaN)
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标识的非正规化的风格，所使用的浮点类型
Original:
identifies the denormalization style used by the floating-point type
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identifies the floating-point types that detect loss of precision as denormalization loss rather than inexact result
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标识的舍入类型所使用的风格
Original:
identifies the rounding style used by the type
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标识IEC 559/IEEE 754浮点类型的
Original:
identifies the IEC 559/IEEE 754 floating-point types
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identifies types that represent a finite set of values
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识别模运算处理溢出的类型
Original:
identifies types that handle overflows with modulo arithmetic
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radix数量的数字，可以表示没有变化
Original:
number of radix digits that can be represented without change
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数的小数位数可以表示没有变化
Original:
number of decimal digits that can be represented without change
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数要区分这种类型的所有值的小数位数
Original:
number of decimal digits necessary to differentiate all values of this type
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基数或用来表示给定类型的整数基地
Original:
the radix or integer base used by the representation of the given type
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一个比最小的负电源是一个有效的标准浮点值的基数
Original:
one more than the smallest negative power of the radix that is a valid normalized floating-point value
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最小的是一个有效的标准浮点值的10的负电源
Original:
the smallest negative power of ten that is a valid normalized floating-point value
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一个比最大的整数次幂的基数是一个有效的有限浮点值
Original:
one more than the largest integer power of the radix that is a valid finite floating-point value
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的最大整数的10次方，这是一个有效的有限浮点值
Original:
the largest integer power of 10 that is a valid finite floating-point value
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标识类型，这可能会导致算术运算陷阱
Original:
identifies types which can cause arithmetic operations to trap
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识别检测tinyness四舍五入前的浮点类型
Original:
identifies floating-point types that detect tinyness before rounding
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[编辑] 成员函数

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返回给定类型的最小的有限值
Original:
returns the smallest finite value of the given type
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返回给定类型的有限值最低
Original:
returns the lowest finite value of the given type
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返回值给定类型的最大有限
Original:
returns the largest finite value of the given type
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返回1.0和下一个可表示的值给定的浮点类型之间的区别
Original:
returns the difference between 1.0 and the next representable value of the given floating-point type
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返回最大的舍入误差浮点型
Original:
returns the maximum rounding error of the given floating-point type
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返回正无穷大值给定的浮点类型
Original:
returns the positive infinity value of the given floating-point type
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返回一个安静的NaN值给定的浮点类型
Original:
returns a quiet NaN value of the given floating-point type
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返回一个信号给定的浮点类型的NaN值
Original:
returns a signaling NaN value of the given floating-point type
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返回值给定的浮点类型的最小正次正规
Original:
returns the smallest positive subnormal value of the given floating-point type
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[编辑] Helper类
表示浮点舍入模式
Original:
indicates floating-point rounding modes
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（枚举） [edit]
表示浮点非规范化模式
Original:
indicates floating-point denormalization modes
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（枚举） [edit]

[编辑] 与C库宏常量的关系

Specialization Members
min() lowest()
（C++11） 		max() epsilon() digits digits10 min_exponent min_exponent10 max_exponent max_exponent10 radix
numeric_limits< bool > 2
numeric_limits< char > CHAR_MIN CHAR_MIN CHAR_MAX 2
numeric_limits< signed char > SCHAR_MIN SCHAR_MIN SCHAR_MAX 2
numeric_limits< unsigned char > ​0​ ​0​ UCHAR_MAX 2
numeric_limits< wchar_t > WCHAR_MIN WCHAR_MIN WCHAR_MAX 2
numeric_limits< char16_t > ​0​ ​0​ UINT_LEAST16_MAX 2
numeric_limits< char32_t > ​0​ ​0​ UINT_LEAST32_MAX 2
numeric_limits< short > SHRT_MIN SHRT_MIN SHRT_MAX 2
numeric_limits< signed short >
numeric_limits< unsigned short > ​0​ ​0​ USHRT_MAX 2
numeric_limits< int > INT_MIN INT_MIN INT_MAX 2
numeric_limits< signed int >
numeric_limits< unsigned int > ​0​ ​0​ UINT_MAX 2
numeric_limits< long > LONG_MIN LONG_MIN LONG_MAX 2
numeric_limits< signed long >
numeric_limits< unsigned long > ​0​ ​0​ ULONG_MAX 2
numeric_limits< long long > LLONG_MIN LLONG_MIN LLONG_MAX 2
numeric_limits< signed long long >
numeric_limits< unsigned long long > ​0​ ​0​ ULLONG_MAX 2
numeric_limits< float > FLT_MIN -FLT_MAX FLT_MAX FLT_EPSILON FLT_MANT_DIG FLT_DIG FLT_MIN_EXP FLT_MIN_10_EXP FLT_MAX_EXP FLT_MAX_10_EXP FLT_RADIX
numeric_limits< double > DBL_MIN -DBL_MAX DBL_MAX DBL_EPSILON DBL_MANT_DIG DBL_DIG DBL_MIN_EXP DBL_MIN_10_EXP DBL_MAX_EXP DBL_MAX_10_EXP FLT_RADIX
numeric_limits< long double > LDBL_MIN -LDBL_MAX LDBL_MAX LDBL_EPSILON LDBL_MANT_DIG LDBL_DIG LDBL_MIN_EXP LDBL_MIN_10_EXP LDBL_MAX_EXP LDBL_MAX_10_EXP FLT_RADIX

[编辑] 为例

#include <limits>
#include <iostream>
 
int main()
{
    std::cout << "type\tlowest\thighest\n";
    std::cout << "int\t"
              << std::numeric_limits<int>::lowest() << '\t'
              << std::numeric_limits<int>::max() << '\n';
    std::cout << "float\t"
              << std::numeric_limits<float>::lowest() << '\t'
              << std::numeric_limits<float>::max() << '\n';
    std::cout << "double\t"
              << std::numeric_limits<double>::lowest() << '\t'
              << std::numeric_limits<double>::max() << '\n';
}

Possible output: 

type    lowest         highest
int     -2147483648    2147483647
float   -3.40282e+38   3.40282e+38
double  -1.79769e+308  1.79769e+308

来自“http://zh.cppreference.com/mwiki/index.php?title=cpp/types/numeric_limits&oldid=27205”