Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help 
std::is_floating_point(3)     C++ Standard Libary    std::is_floating_point(3)

NAME
       std::is_floating_point -	std::is_floating_point

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

	  Checks  whether T is a floating-point	type. Provides the member con-
       stant value which
	  is equal to true, if T is the	type float, double, long  double,  in-
       cluding any
	  cv-qualified variants. Otherwise, value is equal to false.

	  The  behavior	 of  a program that adds specializations for is_float-
       ing_point
	  or is_floating_point_v
	  (since C++17)	is undefined.

Template parameters
	  T - a	type to	check

	 Helper	variable template

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

       Inherited from std::integral_constant

Member constants
	  value	    true if T is a floating-point type (possibly cv-qualified)
       , false
	  [static] otherwise
		   (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>

Possible implementation
	  template< class T >
	  struct is_floating_point
	       : std::integral_constant<
		   bool,
		   std::is_same<float,		  typename	      std::re-
       move_cv<T>::type>::value	 ||
		   std::is_same<double,		   typename	      std::re-
       move_cv<T>::type>::value	 ||
		   std::is_same<long	  double,      typename	      std::re-
       move_cv<T>::type>::value
	       > {};

Example
       // Run this code

	#include <iostream>
	#include <type_traits>

	class A	{};

	int main()
	{
	    std::cout << std::boolalpha;
	    std::cout  <<  "	   A: "	<< std::is_floating_point<A>::value <<
       '\n';
	    std::cout << "  float: "  <<  std::is_floating_point<float>::value
       << '\n';
	    std::cout  << " float&: " << std::is_floating_point<float&>::value
       << '\n';
	    std::cout << " double: " <<	 std::is_floating_point<double>::value
       << '\n';
	    std::cout << "double&: " <<	std::is_floating_point<double&>::value
       << '\n';
	    std::cout  << "    int: " << std::is_floating_point<int>::value <<
       '\n';
	}

Output:
	      A: false
	  float: true
	 float&: false
	 double: true
	double&: false
	    int: false

See also
	  is_iec559	 identifies the	IEC 559/IEEE 754 floating-point	types
	  [static]	 (public static	member constant	 of  std::numeric_lim-
       its<T>)
	  is_integral	 checks	if a type is an	integral type
	  (C++11)	 (class	template)
	  is_arithmetic	 checks	if a type is an	arithmetic type
	  (C++11)	 (class	template)
	  floating_point specifies that	a type is a floating-point type
	  (C++20)	 (concept)

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

Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=std::is_floating_point&sektion=3&manpath=FreeBSD+Ports+15.0>

home | help