std::system_error

Defined in header `<system_error>`
class system_error;		(since C++11)

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

(constructor)	constructs the `system_error` object (public member function)
code	returns error code (public member function)
what [virtual]	returns explanatory string (virtual public member function)

Inherited from std::exception

Member functions

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

Example

#include <thread>
#include <iostream>
#include <system_error>
 
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';
    }
}

Output:

Caught system_error with code generic:22 meaning Invalid argument

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