std::rethrow_exception - cppreference.com (original) (raw)

Throws the previously captured exception object referred-to by the exception pointer p, or a copy of that object.

It is unspecified whether a copy is made. If a copy is made, the storage for it is allocated in an unspecified way.

The behavior is undefined if p is null.

[edit] Parameters

[edit] Exceptions

The exception object referred-to by p if no copy is made.

Otherwise, a copy of such exception object if the implementation successfully copied the exception object.

Otherwise, std::bad_alloc or the exception thrown when copying the exception object, if allocation or copying fails, respectively.

[edit] Notes

Before P1675R2, rethrow_exception was not allowed to copy the exception object, which is unimplementable on some platforms where exception objects are allocated on the stack.

[edit] Example

#include #include #include #include   void handle_eptr(std::exception_ptr eptr) // passing by value is OK { try { if (eptr) std::rethrow_exception(eptr); } catch(const std::exception& e) { std::cout << "Caught exception: '" << e.what() << "'\n"; } }   int main() { std::exception_ptr eptr;   try { [[maybe_unused]] char ch = std::string().at(1); // this generates a std::out_of_range } catch(...) { eptr = std::current_exception(); // capture }   handle_eptr(eptr);   } // destructor for std::out_of_range called here, when the eptr is destructed

Possible output:

Caught exception: 'basic_string::at: __n (which is 1) >= this->size() (which is 0)'

[edit] See also