function
<exception>

std::current_exception

exception_ptr current_exception() noexcept;
Get smart pointer to current exception
Returns an exception_ptr object that points to the currently handled exception, or to a copy of it.

If no exception is being handled, the function returns a null-pointer value.

exception_ptr is a shared smart pointer type: The pointed exception is guaranteed to remain valid for as long as at least one exception_ptr points to it, potentially extending the lifetime of the pointed exception object beyond its scope or across threads. See exception_ptr for more info.

This function throws no exceptions, but if the function is implemented as returning a pointer to a copy of the currently handled exception, it may return a pointer to a different exception if it fails to allocate storage (bad_alloc) or if the copying process fails (it returns the thrown exception or bad_exception, if possible; or some other unspecified value, otherwise).

Parameters

none

Return value

An exception_ptr object pointing to the currently handled exception, or some other exception if the internal process of the function would raise a new exception.

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

Whether the function returns an object that points to the currently handled exception or to a copy of it depends on the particular library implementation.

Exception safety

No-throw guarantee: this function throws no exceptions. Instead, this function uses its return value to signal exceptions thrown during its internal operation.

See also