std::system_error - cppreference.com

From cppreference.com

std::system_error is the type of the exception thrown by various library functions (typically the functions that interface with the OS facilities, e.g. the constructor of std::thread) when the exception has an associated std::error_code, which may be reported.

Inheritance diagram

Member functions

	constructs the `system_error` object (public member function) [edit]
	replaces the `system_error` object (public member function) [edit]
	returns error code (public member function) [edit]
	returns an explanatory string (virtual public member function) [edit]

Inherited from std::exception

Member functions

	destroys the exception object (virtual public member function of `std::exception`) [edit]
	returns an explanatory string (virtual public member function of `std::exception`) [edit]

Example

#include <iostream>
#include <system_error>
#include <thread>

int main()
{
    try
    {
        std::thread().detach(); // attempt to detach a non-thread
    }
    catch(const std::system_error& e)
    {
        std::cout << "Caught system_error with code "
                     "[" << e.code() << "] meaning "
                     "[" << e.what() << "]\n";
    }
}

Possible output:

Caught system_error with code [generic:22] meaning [Invalid argument]