is-abstract-class.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: is_abstract Class	is_abstract Class	11/04/2016	type_traits/std::is_abstract	is_abstract class is_abstract	8867f660-3434-404c-ba90-c26607a5e0d2

is_abstract Class

Tests if type is abstract class.

Syntax

template <classTy> structis_abstract;

Parameters

Ty
The type to query.

Remarks

An instance of the type predicate holds true if the type Ty is a class that has at least one pure virtual function, otherwise it holds false.

Example

// std__type_traits__is_abstract.cpp// compile with: /EHsc #include<type_traits> #include<iostream>structtrivial { int val; }; structabstract { virtualintval() = 0; }; intmain() { std::cout << "is_abstract<trivial> == " << std::boolalpha << std::is_abstract<trivial>::value << std::endl; std::cout << "is_abstract<abstract> == " << std::boolalpha << std::is_abstract<abstract>::value << std::endl; return (0); }

is_abstract<trivial> == false is_abstract<abstract> == true 

Requirements

Header: <type_traits>

Namespace: std

See also

<type_traits>
is_polymorphic Class