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std::is_final(3)	       C++ Standard Libary		std::is_final(3)

NAME
     std::is_final - std::is_final

Synopsis
	Defined in header <type_traits>
	template< class T >		 (since C++14)
	struct is_final;

	std::is_final is a UnaryTypeTrait.

	If  T  is  a final class, provides the member constant value equal true.
     For any other
	type, value is false.

	If T is an incomplete class type, the behavior is undefined.

	If the program adds specializations for std::is_final
	or std::is_final_v
	(since C++17), the behavior is undefined.

Template parameters
	T - a type to check

	Helper variable template

	template< class T >					(since C++17)
	inline constexpr bool is_final_v = is_final<T>::value;

     Inherited from std::integral_constant

Member constants
	value	 true if T is a final class type, false otherwise
	[static] (public static member constant)

Member functions
	operator bool converts the object to bool, returns value
		      (public member function)
	operator()    returns value
	(C++14)       (public member function)

Member types
	Type	   Definition
	value_type bool
	type	   std::integral_constant<bool, value>

Notes
	std::is_final is introduced by the resolution of LWG issue 2112.

	A union can be declared final (and std::is_final will detect that), even
     though
	unions cannot be used as bases in any case.

	Feature-test macro  Value    Std      Feature
	__cpp_lib_is_final 201402L (C++14) std::is_final

Example
     // Run this code

      #include <type_traits>

      class A {};
      static_assert(std::is_final_v<A> == false);

      class B final {};
      static_assert(std::is_final_v<B> == true);

      union U final
      {
	  int x;
	  double d;
      };
      static_assert(std::is_final_v<U> == true);

      int main()
      {
      }

See also
	is_class       checks if a type is a non-union class type
	(C++11)        (class template)
	is_polymorphic checks if a type is a polymorphic class type
	(C++11)        (class template)

http://cppreference.com 	   2024.06.10			std::is_final(3)
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