C++
应用 | Utilities

std::is_compound

STD::是[医]复配

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

如果T是复合类型%28,即数组、函数、对象指针、函数指针、成员对象指针、成员函数指针、引用、类、联合或枚举(包括任何cv限定变量%29)提供成员常量。value平等true.对于任何其他类型,valuefalse...

模板参数

T-a type to check

辅助变量模板

template< class T > inline constexpr bool is_compound_v = is_compound::value;(since C++17)

继承自STD:积分[医]常量

成员常数

value statictrue if T is a compound 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>

注记

复合类型是从基本类型构造的类型。任何C++类型要么是基本类型,要么是复合类型。

可能的实施

模板<class T>结构是[医]复合:STD::整数[医]常数<bool,%21std::is[医]基本<T>*价值>{};

*。

二次

#include <iostream> #include <type_traits> int main() { class cls {}; std::cout << (std::is_compound<cls>::value ? "T is compound" : "T is not a compound") << '\n'; std::cout << (std::is_compound<int>::value ? "T is compound" : "T is not a compound") << '\n'; }

二次

产出:

二次

T is compound T is not a compound

二次

另见

is_fundamental (C++11)checks if a type is fundamental type (class template)
is_scalar (C++11)checks if a type is scalar type (class template)
is_object (C++11)checks if a type is object type (class template)
is_array (C++11)checks if a type is an array 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]复配