is_polymorphic Class

Tests if type has a virtual function.

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

See Also

Reference

<type_traits>

is_abstract Class