A system-specific error code. For more information about the error code, you must look at your platform documentation.
For Windows platforms, this is the Microsoft Developer Network documentation.
The following are common system errors on Windows:
An application-provided error message. The string may or may not be empty. A non-empty error_string provides information
in addition to the stream_error_code. For instance, for a write error (error code 9) the error string is a number showing
how many bytes it was trying to write.
Deprecated. The size of the error string buffer.