std::is_member_pointer
From cppreference.com
| Defined in header <type_traits>
|
||
| template< class T > struct is_member_pointer; |
(since C++11) | |
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 > inline constexpr bool is_member_pointer_v = is_member_pointer<T>::value; |
(since C++17) | |
Inherited from std::integral_constant
Member constants
| value [static] |
true if T is a member 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> |
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
See also
| (C++11) |
checks if a type is a pointer type (class template) |
| (C++11) |
checks if a type is a pointer to a non-static member object (class template) |
| (C++11) |
checks if a type is a pointer to a non-static member function (class template) |