_com_error Class

Microsoft Specific

A _com_error object represents an exception condition detected by the error-handling wrapper functions in the header files generated from the type library or by one of the COM support classes. The _com_error class encapsulates the HRESULT error code and any associated IErrorInfo Interface object.


_com_error Constructs a _com_error object.


operator = Assigns an existing _com_error object to another.

Extractor Functions

Error Retrieves the HRESULT passed to the constructor.
ErrorInfo Retrieves the IErrorInfo object passed to the constructor.
WCode Retrieves the 16-bit error code mapped into the encapsulated HRESULT.

IErrorInfo Functions

Description Calls IErrorInfo::GetDescription function.
HelpContext Calls IErrorInfo::GetHelpContext function.
HelpFile Calls IErrorInfo::GetHelpFile function
Source Calls IErrorInfo::GetSource function.
GUID Calls IErrorInfo::GetGUID function.

Format Message Extractor

ErrorMessage Retrieves the string message for HRESULT stored in the _com_error object.

ExepInfo.wCode to HRESULT Mappers

HRESULTToWCode Maps 32-bit HRESULT to 16-bit wCode.
WCodeToHRESULT Maps 16-bit wCode to 32-bit HRESULT.

END Microsoft Specific


Header: <comdef.h>

Lib: comsuppw.lib or comsuppwd.lib (see /Zc:wchar_t (wchar_t Is Native Type) for more information)

See also

Compiler COM Support Classes
IErrorInfo Interface