std::is_floating_point

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C++
 
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类型的支持
基本类型
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Basic types
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基本类型
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is_floating_point（C++11）
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is_constructible
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is_assignable
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is_copy_assignable
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is_move_assignable
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is_nothrow_move_assignable		（C++11）
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键入特征常数
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Type trait constants
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integral_constant（C++11）
 
Defined in header <type_traits>
template< class T >
struct is_floating_point;
 （C++11 起）
T是一个浮点型（float，double，long double，包括任何CV合格的变种），提供会员value等于true。对于任何其他类型，value是false.
Original:
If T is a floating-point type (float, double, long double, including any cv-qualified variants), provides the member constant value equal true. For any other type, value is false.
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目录

Inherited from std::integral_constant

Member constants

value
[静态的] </ SPAN></div></div>
true如果 T is a floating-point type ，false其他方式
Original:
true if T is a floating-point type , false otherwise
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（公共静态成员常量）

Member functions

operator bool
转换的对象bool，返回value
Original:
converts the object to bool, returns value
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（公共成员函数）

Member types

类型
Original:
Type
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 Definition
value_type bool
type std::integral_constant<bool, value>

</div>

[编辑] 可能的实现

template< class T >
struct is_floating_point : std::integral_constant<
                               bool,
                               std::is_same<float, typename std::remove_cv<T>::type>::value  ||
                               std::is_same<double, typename std::remove_cv<T>::type>::value  ||
                               std::is_same<long double, typename std::remove_cv<T>::type>::value
                           > {};

[编辑] 为例

#include <iostream>
#include <type_traits>
 
class A {};
 
int main()
{
    std::cout << std::boolalpha;
    std::cout << std::is_floating_point<A>::value << '\n';
    std::cout << std::is_floating_point<float>::value << '\n';
    std::cout << std::is_floating_point<int>::value << '\n';
}

Output: 

false
true
false

[编辑] 另请参阅

[静态的] </ SPAN></div></div>
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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（公共静态成员常量of std::numeric_limits） [edit]
（C++11）
检查如果一个类型是整数类型
Original:
checks if a type is integral type
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（类模板） [edit]
（C++11）
如果一个类型的检查是算术型
Original:
checks if a type is arithmetic type
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（类模板） [edit]

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