std::is_member_pointer
From cppreference.com
Defined in header <type_traits>
|
||
template< class T > struct is_member_pointer; |
(since C++11) | |
std::is_member_pointer
is a UnaryTypeTrait.
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.
If the program adds specializations for std::is_member_pointer
or std::is_member_pointer_v
, the behavior is undefined.
Contents |
[edit] Template parameters
T | - | a type to check |
[edit] 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> |
[edit] 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> {}; |
[edit] Example
Run this code
#include <type_traits> class C {}; static_assert(std::is_member_pointer_v<int(C::*)>); static_assert(!std::is_member_pointer_v<int>); int main() { }
[edit] 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) |