is_polymorphic Class
The latest version of this topic can be found at is_polymorphic Class.
Tests if type has a virtual function.
Syntax
template <class Ty>
struct is_polymorphic;
Parameters
Ty
The type to query.
Remarks
An instance of the type predicate holds true if the type Ty is a class that declares or inherits a virtual function, otherwise it holds false.
Example
// std_tr1__type_traits__is_polymorphic.cpp
// compile with: /EHsc
#include <type_traits>
#include <iostream>
struct trivial
{
int val;
};
struct throws
{
throws() throw(int)
{
}
throws(const throws&) throw(int)
{
}
throws& operator=(const throws&) throw(int)
{
}
virtual ~throws()
{
}
int val;
};
int main()
{
std::cout << "is_polymorphic<trivial> == " << std::boolalpha
<< std::is_polymorphic<trivial>::value << std::endl;
std::cout << "is_polymorphic<throws> == " << std::boolalpha
<< std::is_polymorphic<throws>::value << std::endl;
return (0);
}
is_polymorphic<trivial> == false
is_polymorphic<throws> == true
Requirements
Header: <type_traits>
Namespace: std