std::is_pointer

From cppreference.com

Defined in header `<type_traits>`

template< class T > struct is_pointer;		(since C++11)

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.

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)

Member types


Type	Definition

`value_type`	`bool`

`type`	std::integral_constant<bool, value>

[edit] 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> {};

[edit] Example

run this code

#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

[edit] See also


is_array (C++11)	checks if a type is an array type (class template)

is_scalar (C++11)	checks if a type is scalar type (class template)

Language
Standard library headers
Concepts
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)