std:: future_error

The class std::future_error defines an exception object that is thrown on failure by the functions in the thread library that deal with asynchronous execution and shared states ( std::future , std::promise , etc). Similar to std::system_error , this exception carries an error code compatible with std::error_code .

Inheritance diagram

Member functions

Example

#include <future>
#include <iostream>
 
int main()
{
    std::future<int> empty;
    try
    {
        int n = empty.get(); // The behavior is undefined, but
                             // some implementations throw std::future_error
    }
    catch (const std::future_error& e)
    {
        std::cout << "Caught a future_error with code \"" << e.code()
                  << "\"\nMessage: \"" << e.what() << "\"\n";
    }
}

Caught a future_error with code "future:3"
Message: "No associated state"

See also