The concurrency support library also supports passing exceptions via a future object.  

Let's understand the exception concurrency handling mechanism with a simple example, as follows:

#include <iostream>
#include <future>
#include <promise>
using namespace std;
 
void add ( int firstInput, int secondInput, promise<int> output ) {
  try {
         if ( ( INT_MAX == firstInput ) || ( INT_MAX == secondInput ) )
             output.set_exception( current_exception() ) ;
        }
  catch(...) {}

       output.set_value( firstInput + secondInput ) ;

}

int main ( ) {


     try {
    promise<int> promise_;
          future<int> output = promise_.get_future();
    async ( launch::deferred, add, INT_MAX, INT_MAX, move(promise_) );
          cout << "The sum of INT_MAX + INT_MAX is " << output.get ( ) << endl;
     }
     catch( exception e ) {
  cerr << "Exception occured" << endl;
     }
}

Just like the way we passed the output messages to the caller function/thread, the concurrency support library also allows you to set the exception that occurred within the task or asynchronous function. When the caller thread invokes the future::get() method, the same exception will be thrown, hence communicating exceptions is made easy.