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std::expected::value(3)        C++ Standard Libary	 std::expected::value(3)

NAME
     std::expected::value - std::expected::value

Synopsis
	T is not (possibly cv-qualified) void
	constexpr T& value() &; 	      (1) (since C++23)
	constexpr const T& value() const&;    (2) (since C++23)
	constexpr T&& value() &&;	      (3) (since C++23)
	constexpr const T&& value() const&&;  (4) (since C++23)
	T is (possibly cv-qualified) void
	constexpr void value() const&;	      (5) (since C++23)
	constexpr void value() &&;	      (6) (since C++23)

	If  *this  contains  an  expected value, returns a reference to the con-
     tained value.
	Returns nothing if T is (possibly cv-qualified) void.

	Otherwise, throws an exception of type std::bad_expected_access<std::de-
     cay_t<E>>
	that contains a copy of error().

	1,2) If std::is_copy_constructible_v<E> is false, the  program	is  ill-
     formed.
	3,4) If std::is_copy_constructible_v<E> or std::is_constructible_v<E,
	decltype(std::move(error()))> is false, the program is ill-formed.
	5)  If	std::is_copy_constructible_v<E>  is  false,  the program is ill-
     formed.
	6) If std::is_move_constructible_v<E> is  false,  the  program	is  ill-
     formed.

Parameters
	(none)

Return value
	1-4) The expected value contained in *this.
	5,6) (none)

Exceptions
	1,2,5)	Throws std::bad_expected_access(std::as_const(error())) if *this
     contains an
	unexpected value.
	3,4,6) Throws std::bad_expected_access(std::move(error())) if *this con-
     tains an
	unexpected value.

Example
	 This section is incomplete
	 Reason: no example

	Defect reports

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

	   DR	 Applied to		 Behavior as published		    Cor-
     rect behavior
	LWG  3940 C++23      E was not required to be			     re-
     quired
			    copy/move-constructible for overloads (5,6)

See also
	value_or	    returns the expected value if present, another value
     otherwise
			    (public member function)
	operator->	    accesses the expected value
	operator*	    (public member function)
	error		    returns the unexpected value
			    (public member function)
	bad_expected_access exception indicating checked access to  an	expected
     that contains
	(C++23) 	    an unexpected value
			    (class template)

Category:
	  * Todo no example

http://cppreference.com 	   2024.06.10		 std::expected::value(3)
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