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Difference between revisions of "cpp/error/unexpected"

From cppreference.com
< cpp‎ | error
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void unexpected();
 
void unexpected();
 
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If a destructor reset the unexpected handler during stack unwinding and the unwinding later led to {{tt|unexpected}} being called, the handler that was installed at the end of the throw expression is the one that will be called. (note: it was ambiguous whether re-throwing applied the new handlers)
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If a destructor reset the unexpected handler during stack unwinding and the unwinding later led to {{tt|unexpected}} being called, the handler that was installed at the end of the throw expression is the one that will be called (note: it was ambiguous whether re-throwing applied the new handlers).
 
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===Exceptions===
 
===Exceptions===
Throw any exception thrown by the currently installed {{lc|std::unexpected_handler}}
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Throw any exception thrown by the currently installed {{lc|std::unexpected_handler}}.
  
 
===Defect reports===
 
===Defect reports===
 
{{dr list begin}}
 
{{dr list begin}}
{{dr list item|wg=lwg|dr=2111|std=C++11|before=effect of calling {{tt|set_unexpected}} during stack unwinding differs from C++98 and breaks some ABIs |after=made unspecified}}
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{{dr list item|wg=lwg|dr=2111|std=C++11|before=effect of calling {{tt|set_unexpected}} during stack unwinding differs from C++98 and breaks some ABIs|after=made unspecified}}
 
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===See also===
 
===See also===
 
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{{dsc inc | cpp/utility/expected/dsc unexpected}}
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{{dsc inc|cpp/utility/expected/dsc unexpected}}
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{{dsc inc|cpp/error/dsc unexpected_handler}}
 
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Revision as of 05:28, 16 July 2023

 
 
 
Defined in header <exception>
void unexpected();
(until C++11)
[[noreturn]] void unexpected();
(since C++11)
(deprecated)
(removed in C++17)

std::unexpected() is called by the C++ runtime when a dynamic exception specification is violated: an exception is thrown from a function whose exception specification forbids exceptions of this type.

std::unexpected() may also be called directly from the program.

In either case, std::unexpected calls the currently installed std::unexpected_handler. The default std::unexpected_handler calls std::terminate.

If a destructor reset the unexpected handler during stack unwinding and the unwinding later led to unexpected being called, the handler that was installed at the end of the throw expression is the one that will be called (note: it was ambiguous whether re-throwing applied the new handlers).

(until C++11)

If a destructor reset the unexpected handler during stack unwinding, it is unspecified which handler is called if the unwinding later led to unexpected being called.

(since C++11)

Contents

Parameters

(none)

Return value

(none)

Exceptions

Throw any exception thrown by the currently installed std::unexpected_handler.

Defect reports

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

DR Applied to Behavior as published Correct behavior
LWG 2111 C++11 effect of calling set_unexpected during stack unwinding differs from C++98 and breaks some ABIs made unspecified

See also

represented as an unexpected value
(class template) [edit]
(deprecated in C++11)(removed in C++17)
the type of the function called by std::unexpected
(typedef) [edit]