std::is_arithmetic

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定义于头文件 <type_traits>
template< class T >
struct is_arithmetic;
(C++11 起)

If T is an arithmetic type (that is, an integral type or a floating-point type), provides the member constant value equal true. For any other type, value is false.

目录

继承自 std::integral_constant

成员常量

value
[静态]
T is an arithmetic type 则为true,否则为false
(公开静态成员常量)

成员函数

operator bool
转换对象为bool,返回value
(公开成员函数)
operator()
(C++14)
返回value
(公开成员函数)

成员类型

类型 定义
value_type bool
type std::integral_constant<bool, value>

[编辑] 注释

Arithmetic types are the types for which the built-in 算术运算符 (+, -, *, /) are defined (possibly in combination with the usual arithmetic conversions)

Specializations of std::numeric_limits are provided for all arithmetic types.

[编辑] 可能的实现

template< class T >
struct is_arithmetic : std::integral_constant<bool,
                                              std::is_integral<T>::value ||
                                              std::is_floating_point<T>::value> {};

[编辑] 示例

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

输出:

false
true
false
false
true
false
false

[编辑] 另请参阅

检查类型是否为整型
(类模板) [edit]
检查类型是否是浮点类型
(类模板) [edit]