Std::is_pointer (3) Linux Manual Page

std::is_pointer – std::is_pointer

Synopsis

Defined in header<type_traits>

    template <class T>
    (since C++ 11)

        struct is_pointer;

Checks whether T is a pointer_to_object or a pointer to function (but not a pointer to member/member function). Provides the member constant value which is equal to true, if T is a object/function pointer type. Otherwise, value is equal to false.

Template parameters

T – a type to check

Helper variable template

template< class T > (since C++17)
inline constexpr bool is_pointer_v = is_pointer<T>::value;

Inherited from std::integral_constant

Member constants

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

Member functions

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

operator() returns value
(public member function)
(C++14)

Member types

Type Definition
value_type bool
type std::integral_constant<bool, value>

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

// 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<A &>::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';
    std::cout << std::is_pointer<int[10]>::value << '\n';
    std::cout << std::is_pointer<std::nullptr_t>::value << '\n';
}

Output:

  false
  true
  false
  false
  true
  true
  false
  false

is_member_pointer checks if a type is a pointer to an non-static member function or object
                           (class template)
(C++11)
is_member_object_pointer checks if a type is a pointer to a non-static member object
                           (class template)
(C++11)
is_member_function_pointer checks if a type is a pointer to a non-static member function
                           (class template)
(C++11)
is_array checks if a type is an array type
                           (class template)
(C++11)
is_scalar checks if a type is a scalar type
                           (class template)
(C++11)

std::is_pointer (3) Linux Manual Page