std::is_member_function_pointer - cppreference.com (original) (raw)
| | | | | ---------------------------------------------------------- | | ------------- | | template< class T > struct is_member_function_pointer; | | (since C++11) |
std::is_member_function_pointer is a UnaryTypeTrait.
Checks whether T is a non-static member function pointer. Provides the member constant value which is equal to true, if T is a non-static member function pointer type. Otherwise, value is equal to false.
If the program adds specializations for std::is_member_function_pointer or std::is_member_function_pointer_v, the behavior is undefined.
Contents
[edit] Template parameters
[edit] Helper variable template
| template< class T > constexpr bool is_member_function_pointer_v = is_member_function_pointer<T>::value; | | (since C++17) | | ------------------------------------------------------------------------------------------------------------------ | | ------------- |
Inherited from std::integral_constant
Member constants
| | true if T is a member function pointer type, false otherwise (public static member constant) | | ----------------------------------------------------------------------------------------------- |
Member functions
| | converts the object to bool, returns value (public member function) | | ---------------------------------------------------------------------- | | | returns value (public member function) |
Member types
[edit] Possible implementation
template struct is_member_function_pointer_helper : std::false_type {}; template<class T, class U> struct is_member_function_pointer_helper<T U::*> : std::is_function {}; template struct is_member_function_pointer : is_member_function_pointer_helper<typename std::remove_cv::type> {};
[edit] Example
#include class A { public: void member() {} }; int main() { // fails at compile time if A::member is a data member and not a function static_assert(std::is_member_function_pointer<decltype(&A::member)>::value, "A::member is not a member function."); }