std::system_error::system_error
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                    < cpp | error | system error
                    
                                                            
                    | system_error( std::error_code ec ); | (1) | (since C++11) | 
| system_error( std::error_code ec, const std::string& what_arg ); | (2) | (since C++11) | 
| system_error( std::error_code ec, const char* what_arg ); | (2) | (since C++11) | 
| system_error( int ev, const std::error_category& ecat ); | (3) | (since C++11) | 
| system_error( int ev, const std::error_category& ecat, const std::string& what_arg); | (4) | (since C++11) | 
| system_error( int ev, const std::error_category& ecat, const char* what_arg); | (4) | (since C++11) | 
Constructs new system error object.
1) Constructs with error code 
ec2) Constructs with error code 
ec and explanation string what_arg. The string returned by what() is guaranteed to contain what_arg.3) Constructs with underlying error code 
ev and associated error category ecat.4) Constructs with underlying error code 
ev, associated error category ecat and explanatory string what_arg. The string returned by what() is guaranteed to contain what_arg.[edit] Parameters
| ec | - | error code | 
| ev | - | error code in base encoding | 
| ecat | - | the category of error | 
| what_arg | - | explanatory string | 
[edit] Example
Demonstrates how to create a system_error exception from a errno value
Run this code
#include <iostream> #include <system_error> int main() { try { throw std::system_error(EDOM, std::generic_category()); } catch (const std::system_error& error) { std::cout << "Error: " << error.code() << " - " << error.code().message() << '\n'; } }
Possible output:
Error: generic:33 - Numerical argument out of domain


