function
<exception>

std::rethrow_exception

[[noreturn]] void rethrow_exception (exception_ptr p);
Rethrow exception
Throws the exception object pointed by p.

Parameters

p
An exception_ptr object pointing to an exception object.
This argument shall not be a null exception_ptr.
exception_ptr is a pointer-like type that points to exceptions.

Return value

none (the function never returns).

Example

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// exception_ptr example
#include <iostream>       // std::cout
#include <exception>      // std::exception_ptr, std::current_exception, std::rethrow_exception
#include <stdexcept>      // std::logic_error

int main () {
  std::exception_ptr p;
  try {
     throw std::logic_error("some logic_error exception");   // throws
  } catch(const std::exception& e) {
     p = std::current_exception();
     std::cout << "exception caught, but continuing...\n";
  }

  std::cout << "(after exception)\n";

  try {
     std::rethrow_exception (p);
  } catch (const std::exception& e) {
     std::cout << "exception caught: " << e.what() << '\n';
  }
  return 0;
}

Output:

exception caught, but continuing...
(after exception)
exception caught: some logic_error exception


Data races

Concurrently calling rethrow_exception on exception_ptr objects that refer to the same exception is safe.

Note though that some implementations may not perform a copy of the pointed object on entering the catch exception handling block, and concurrently accessing the rethrown exception object in this case may introduce a data race.

Exception safety

Throws an exception.

If p is a null exception_ptr, it causes undefined behavior.

See also