std::is_member_pointer (3) - Linux Manuals

std::is_member_pointer: std::is_member_pointer

NAME

std::is_member_pointer - std::is_member_pointer

Synopsis

Defined in header <type_traits>
template< class T > (since C++11)
struct is_member_pointer;

If T is pointer to non-static member object or a pointer to non-static member function, provides the member constant value equal true. For any other type, value is false.

Template parameters

T - a type to check

Helper variable template

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

Inherited from std::integral_constant

Member constants

value true if T is a member 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_member_pointer_helper : std::false_type {};

  template< class T, class U >
  struct is_member_pointer_helper<T U::*> : std::true_type {};

  template< class T >
  struct is_member_pointer :
      is_member_pointer_helper<typename std::remove_cv<T>::type> {};

Example

// Run this code

  #include <iostream>
  #include <type_traits>

  int main() {
      class cls {};
      std::cout << (std::is_member_pointer<int(cls::*)>::value
                       ? "T is member pointer"
                       : "T is not a member pointer") << '\n';
      std::cout << (std::is_member_pointer<int>::value
                       ? "T is member pointer"
                       : "T is not a member pointer") << '\n';
  }

Output:

  T is member pointer
  T is not a member pointer