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std::is_member_pointer

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< cpp‎ | types
 
 
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is_member_pointer
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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

#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

checks if a type is a pointer type
(class template) [edit]
checks if a type is a pointer to a non-static member object
(class template) [edit]
checks if a type is a pointer to a non-static member function
(class template) [edit]