std::is_arithmetic
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在头文件 <type_traits> 中定义
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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 |
Inherited from std::integral_constant
Member constants
value [静态的]</div></div>
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true如果 T is an arithmetic type ,false其他方式 原文: true if T is an arithmetic type , false otherwise (公共静态成员常量) |
Member functions
operator bool |
转换的对象bool,返回 value 原文: converts the object to bool, returns value (公共成员函数) |
Member types
类型
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Definition |
value_type
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bool
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type
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std::integral_constant<bool, value> |
</div>
[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
(C++11) |
检查类型是否为整型 (类模板) |
(C++11) |
检查类型是否是浮点类型 (类模板) |