type
<exception>
std::unexpected_handler
typedef void (*unexpected_handler)();
Type of unexpected handler function
This is a typedef of a void function with no parameters, used as the argument and return type in function set_unexpected.
An unexpected handler function is a function called when a function throws an exception that is not in its dynamic-exception-specification (i.e., in its throw specifier).
For more info, see the reference for set_unexpected, which is the function used to set a function of this type as the active unexpected handler.
Compatibility
The use of dynamic-exception-specifiers is deprecated (since C++11).