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

NAME
       std::is_bind_expression - std::is_bind_expression

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

	  If   T  is  a	 type  produced	 by  a	call  to  std::bind  (but  not
       std::bind_front or
	  std::bind_back), this	template is derived from  std::true_type.  For
       any other type
	  (unless   user-specialized),	 this	template   is	derived	  from
       std::false_type.

	  A program may	specialize this	template for a program-defined type  T
       to implement
	  UnaryTypeTrait  with	base characteristic of std::true_type to indi-
       cate that T should
	  be treated by	std::bind as if	it were	the type of a bind  subexpres-
       sion: when a
	  bind-generated  function object is invoked, a	bound argument of this
       type will be
	  invoked as a function	object and will	be given all the unbound argu-
       ments passed to
	  the bind-generated object.

Member constants
	  value	   true	if T is	a  function  object  generated	by  std::bind,
       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 <functional>
	#include <iostream>
	#include <type_traits>

	struct MyBind
	{
	    typedef int	result_type;
	    int	operator()(int a, int b) const { return	a + b; }
	};

	namespace std
	{
	    template<>
	    struct is_bind_expression<MyBind> :	public true_type {};
	}

	int f(int n1, int n2)
	{
	    return n1 +	n2;
	}

	int main()
	{
	    // as if bind(f, bind(MyBind(), _1,	_2), 2)
	    auto b = std::bind(f, MyBind(), 2);

	    std::cout  <<  "Adding  2 to the sum of 10 and 11 gives " << b(10,
       11) << '\n';
	}

Output:
	Adding 2 to the	sum of 10 and 11 gives 23

	  Defect reports

	  The following	behavior-changing defect reports were applied retroac-
       tively to
	  previously published C++ standards.

	     DR	   Applied to	      Behavior as  published	       Correct
       behavior
	  LWG 2010 C++11      program-defined specializations could can	be de-
       rived from
			      only    be    derived    from    std::false_type
       std::true_type

See also
	  bind	  binds	one or more arguments to a function object
	  (C++11) (function template)

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

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