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

NAME
       std::is_integral	- std::is_integral

Synopsis
	  Defined in header <type_traits>
	  template< class T >		   (since C++11)
	  struct is_integral;

	  Checks  whether  T is	an integral type. Provides the member constant
       value which is
	  equal	to true, if T is the type bool,	char
	  , char8_t
	  (since C++20), char16_t, char32_t, wchar_t, short, int,  long,  long
       long, or	any
	  implementation-defined extended integer types, including any signed,
       unsigned, and
	  cv-qualified variants. Otherwise, value is equal to false.

	  The behavior of a program that adds specializations for is_integral
	  or is_integral_v
	  (since C++17)	is undefined.

Template parameters
	  T - a	type to	check

	 Helper	variable template

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

       Inherited from std::integral_constant

Member constants
	  value	   true	if T is	an integral 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>

Example
       // Run this code

	#include <iostream>
	#include <iomanip>
	#include <type_traits>

	class A	{};

	enum E : int {};

	template <class	T>
	T f(T i)
	{
	    static_assert(std::is_integral<T>::value, "Integral	required.");
	    return i;
	}

	#define	SHOW(...) std::cout << std::setw(29) <<	#__VA_ARGS__ <<	" == "
       << __VA_ARGS__ << '\n'

	int main()
	{
	    std::cout << std::boolalpha;

	    SHOW( std::is_integral<A>::value );
	    SHOW( std::is_integral_v<E>	);
	    SHOW( std::is_integral_v<float> );
	    SHOW( std::is_integral_v<int> );
	    SHOW( std::is_integral_v<const int>	);
	    SHOW( std::is_integral_v<bool> );
	    SHOW( f(123) );
	}

Output:
	   std::is_integral<A>::value == false
		std::is_integral_v<E> == false
	    std::is_integral_v<float> == false
	      std::is_integral_v<int> == true
	std::is_integral_v<const int> == true
	     std::is_integral_v<bool> == true
			       f(123) == 123

See also
	  integral	    specifies that a type is an	integral type
	  (C++20)	    (concept)
	  is_integer	    identifies integer types
	  [static]	      (public	static	member	constant  of  std::nu-
       meric_limits<T>)
	  is_floating_point checks if a	type is	a floating-point type
	  (C++11)	    (class template)
	  is_arithmetic	    checks if a	type is	an arithmetic type
	  (C++11)	    (class template)
	  is_enum	    checks if a	type is	an enumeration type
	  (C++11)	    (class template)

http://cppreference.com		  2022.07.31		   std::is_integral(3)

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