std::get_unexpected
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                    |   Defined in header  <exception>
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|   std::unexpected_handler get_unexpected() noexcept;  | 
 (since C++11)  (deprecated) (removed in C++17)  | 
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Returns the currently installed std::unexpected_handler, which may be a null pointer.
This function is thread-safe. Prior call to std::set_unexpected synchronizes-with (see std::memory_order) the subsequent calls to this function.
Parameters
(none)
Return value
The currently installed std::unexpected_handler.
See also
|    (removed in C++17)  | 
    the type of the function called by std::unexpected   (typedef)  | 
|    (removed in C++17)  | 
   changes the function to be called by std::unexpected  (function)  |