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std::expected<T,E>::error

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< cpp‎ | utility‎ | expected
 
 
Utilities library
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Relational operators (deprecated in C++20)
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constexpr const E& error() const& noexcept;
(1) (since C++23)
constexpr E& error() & noexcept;
(2) (since C++23)
constexpr const E&& error() const&& noexcept;
(3) (since C++23)
constexpr E&& error() && noexcept;
(4) (since C++23)

Accesses the unexpected value contained in *this.

If has_value() is true, the behavior is undefined.

(until C++26)

If has_value() is true:

  • If the implementation is hardened, a contract violation occurs. Moreover, if the contract-violation handler returns under "observe" evaluation semantic, the behavior is undefined.
  • If the implementation is not hardened, the behavior is undefined.
(since C++26)

[edit] Return value

1,2) unex
3,4) std::move(unex  )

[edit] Example

This section is incomplete
Reason: no example

[edit] See also

returns the unexpected value if present, another value otherwise
(public member function) [edit]
accesses the expected value
(public member function) [edit]
returns the expected value
(public member function) [edit]
checks whether the object contains an expected value
(public member function) [edit]
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