| 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 > 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
#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) |
| std::experimental::is_member_pointer_v
(library fundamentals TS) | variable template alias of std::is_member_pointer::value (variable template) |
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