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std::refere...m_temporary(3)   C++ Standard Libary  std::refere...m_temporary(3)

NAME
     std::reference_converts_from_temporary  - std::reference_converts_from_tem-
     porary

Synopsis
	Defined in header <type_traits>
	template< class T, class U >		   (since C++23)
	struct reference_converts_from_temporary;

	Let V be std::remove_cv_t<U> if U is a scalar type or cv void, or U oth-
     erwise. If T
	is a reference type, and given a hypothetic expression e such  that  de-
     cltype(e) is V,
	the  variable definition T ref = e; is well-formed and binds a temporary
     object to
	ref, then provides the member constant value equal to  true.  Otherwise,
     value is
	false.

	If  T is an lvalue reference type to a const- but not volatile-qualified
     object type
	or an rvalue reference type, both std::remove_reference_t<T> and
	std::remove_reference_t<U> shall be complete types, cv void, or  an  ar-
     rays of unknown
	bound; otherwise the behavior is undefined.

	If an instantiation of a template above depends, directly or indirectly,
     on an
	incomplete  type,  and that instantiation could yield a different result
     if that type
	were hypothetically completed, the behavior is undefined.

	If   the   program   adds   specializations   for    std::reference_con-
     verts_from_temporary or
	std::reference_converts_from_temporary_v, the behavior is undefined.

Member constants
		 true if T is a reference type, a U value can be bound to T in
	value	  copy-initialization,	and a temporary object would be bound to
     the
	[static] reference, false 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>

Notes
	std::reference_converts_from_temporary can be used  for  rejecting  some
     cases that
	always produce dangling references.

Example
     // Run this code

      #include <type_traits>

      int main() {}

      static_assert(std::reference_converts_from_temporary_v<int&&,    int>   ==
     true);
      static_assert(std::reference_converts_from_temporary_v<const int&, int> ==
     true);
      static_assert(std::reference_converts_from_temporary_v<int&&,  int&&>   ==
     false);
      static_assert(std::reference_converts_from_temporary_v<const  int&, int&&>
     == false);
      static_assert(std::reference_converts_from_temporary_v<int&&,  long&&>  ==
     true);
      static_assert(std::reference_converts_from_temporary_v<int&&,   long>   ==
     true);

See also
	is_convertible
	is_nothrow_convertible checks if a type can be converted  to  the  other
     type
	(C++11) 	       (class template)
	(C++20)
	invoke		       invokes any Callable object with given arguments
	invoke_r	       and possibility to specify return type
	(C++17) 	       (since C++23)
	(C++23) 	       (function template)
	bind		       binds one or more arguments to a function object
	(C++11) 	       (function template)
	visit			calls  the  provided  functor with the arguments
     held by one or
	(C++17) 	       more variants
			       (function template)
	constructor	       constructs a new std::function instance
			       (public	  member    function	of    std::func-
     tion<R(Args...)>)
	constructor	       constructs a new std::move_only_function object
	(C++23) 		(public  member function of std::move_only_func-
     tion)
			       constructs the task object
	constructor		 (public   member   function	of    std::pack-
     aged_task<R(Args...)>)

http://cppreference.com 	   2024.06.10	    std::refere...m_temporary(3)
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