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std::is_object

STD：：是[医]对象

Defined in header ​​
template< class T > struct is_object;​(since C++11)

如果T是对象类型%28，这可能是cv限定类型，但函数、引用或void类型%29，提供成员常量value平等true.对于任何其他类型，value是false...

模板参数

T-a type to check

辅助变量模板

template< class T > inline constexpr bool is_object_v = is_object::value;​(since C++17)

继承自STD：积分[医]常量

成员常数

value statictrue if T is an object type , false otherwise (public static member constant)

成员函数

operator boolconverts the object to bool, returns value (public member function)
operator() (C++14)returns value (public member function)

成员类型

TypeDefinition
value_typebool
typestd::integral_constant<bool, value>

可能的实施

模板<class T>结构是[医]目的：STD：：整数[医]常数<bool，std：：is[医]标量<T>*价值STD：：是[医]列阵<T>*价值STD：：是[医]联合<T>*价值STD：：是[医]类<T>*价值>{}；

*。

例

二次

#include <iostream>
#include <type_traits>
 
int main() {
    class cls {};
    std::cout << std::boolalpha;
    std::cout << std::is_object<int>::value << '\n';
    std::cout << std::is_object<int&>::value << '\n';
    std::cout << std::is_object<cls>::value << '\n';
    std::cout << std::is_object<cls&>::value << '\n';
}

二次

产出：

二次

true
false
true
false

二次

另见

is_scalar (C++11)checks if a type is scalar type (class template)
is_array (C++11)checks if a type is an array type (class template)
is_union (C++11)checks if a type is an union type (class template)
is_class (C++11)checks if a type is a non-union class type (class template)

 © cppreference.com

在CreativeCommonsAttribution下授权-ShareAlike未移植许可v3.0。

http：//en.cppreference.com/w/cpp/type/is[医]对象

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