NAME¶

std::system_error - std::system_error

Synopsis¶

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.

std-system error-inheritance.svg

Inheritance diagram

Member functions¶

constructor constructs the system_error object
(public member function)
operator= replaces the system_error object
(public member function)
code returns error code
(public member function)
what returns an explanatory string
[virtual] (virtual public member function)

Inherited from std::exception

Member functions¶

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

Example¶

// Run this code

#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';
}
}

Possible output:¶

Caught system_error with code generic:22 meaning Invalid argument