Namespaces
Variants
Views
Actions

std::is_pointer

From cppreference.com
< cpp‎ | types
Revision as of 16:07, 2 November 2012 by P12bot (Talk | contribs)

 
 
 
Type support
Basic types
Fundamental types
Fixed width integer types (C++11)
Numeric limits
C numeric limits interface
Runtime type information
Type traits
Primary type categories
(C++11)
(C++11)
is_pointer
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
Type properties
(C++11)
(C++11)
(C++11)
(C++14)
Supported operations
Relationships and property queries
(C++11)
(C++11)
(C++11)
(C++11)
Type modifications
(C++11)(C++11)(C++11)
Type transformations
(C++11)
(C++11)
(C++11)
Type trait constants
 

Template:ddcl list begin <tr class="t-dsc-header">

<td>
Defined in header <type_traits>
</td>

<td></td> <td></td> <tr class="t-dcl ">

<td >
template< class T >
struct is_pointer;
</td>

<td class="t-dcl-nopad"> </td> <td > (since C++11) </td> </tr> Template:ddcl list end

If T is an object pointer type or a function pointer type (but not pointer to non-static member object or member function), provides the member constant value equal true. For any other type, value is false.

Contents

Inherited from std::integral_constant

Member constants

value
[static]
true if T is a pointer type , false otherwise
(public static member constant)

Member functions

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

Member types

Type Definition
value_type bool
type std::integral_constant<bool, value>
[edit template]

Possible implementation

template< class T > struct is_pointer_helper     : std::false_type {};
template< class T > struct is_pointer_helper<T*> : std::true_type {};
template< class T > struct is_pointer : is_pointer_helper<typename std::remove_cv<T>::type> {};

Example

#include <iostream>
#include <type_traits>
 
class A {};
 
int main() 
{
    std::cout << std::boolalpha;
    std::cout << std::is_pointer<A>::value << '\n';
    std::cout << std::is_pointer<A*>::value << '\n';
    std::cout << std::is_pointer<float>::value << '\n';
    std::cout << std::is_pointer<int>::value << '\n';
    std::cout << std::is_pointer<int*>::value << '\n';
    std::cout << std::is_pointer<int**>::value << '\n';
}

Output:

false
true
false
false
true
true

See also

(C++11)
checks if a type is an array type
(class template) [edit]
(C++11)
checks if a type is scalar type
(class template) [edit]