HRESULTFROMWIN32x

HRESULTFROMWIN32 is a macro in the Windows API used to convert a Win32 error code into an HRESULT value. HRESULT is a 32-bit value used to encode error information in COM (Component Object Model) and other Windows APIs. The macro is defined in the Winerror.h header file and is used to create an HRESULT value from a Win32 error code.

The HRESULT value is structured as follows: the most significant bit is the severity bit, the next 15 bits are the facility code, and the remaining 16 bits are the error code. The severity bit is set to 1 for errors and 0 for success. The facility code identifies the subsystem that originated the error. The error code is the actual error code.

The HRESULTFROMWIN32 macro takes a Win32 error code as its parameter and returns an HRESULT value. The macro sets the severity bit to 1, the facility code to FACILITY_WIN32 (7), and the error code to the Win32 error code. The resulting HRESULT value can be used to indicate an error in a COM method or other Windows API function.

The HRESULTFROMWIN32 macro is useful when converting Win32 error codes to HRESULT values for use in COM or other Windows APIs. It provides a standardized way to encode error information and makes it easier to handle errors in a consistent manner.