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std::experi...onal::value(3)   C++ Standard Libary  std::experi...onal::value(3)

NAME
     std::experimental::optional::value - std::experimental::optional::value

Synopsis
	constexpr T& value() &; 	      (1) (library fundamentals TS)
	constexpr const T & value() const &;
	constexpr T&& value() &&;	      (2) (library fundamentals TS)
	constexpr const T&& value() const &&;

	Returns the contained value.

	1)  Equivalent	to  return  bool(*this)  ? *val : throw bad_optional_ac-
     cess();.
	2) Equivalent to return bool(*this) ? std::move(*val) : throw
	bad_optional_access();.

Parameters
	(none)

Return value
	A reference to the contained value.

Exceptions
	std::experimental::bad_optional_access	if  *this  does  not  contain  a
     value.

Notes
	The  dereference  operator  operator*()  does not check if this optional
     contains a
	value, which may be more efficient than value().

Example
     // Run this code

      #include <experimental/optional>
      #include <iostream>

      int main()
      {
	  std::experimental::optional<int> opt = {};

	  try
	  {
	      int n = opt.value();
	  }
	  catch (const std::logic_error& e)
	  {
	      std::cout << e.what() << '\n';
	  }
      }

Possible output:
      optional<T>::value: not engaged

See also
				  returns the contained value if available,  an-
     other value
	value_or		  otherwise
				  (public member function)
	operator->		  accesses the contained value
	operator*		  (public member function)
	bad_optional_access	   exception indicating checked access to an op-
     tional that
	(library fundamentals TS) doesn't contain a value
				  (class)

Category:
	  * Noindexed pages

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